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Sample records for stimulated subsurface bioremediation

  1. Geophysical Monitoring of Coupled Microbial and Geochemical Processes During Stimulated Subsurface Bioremediation

    SciTech Connect

    Williams, Kenneth H.; Kemna, Andreas; Wilkins, Michael J.; Druhan, Jennifer L.; Arntzen, Evan V.; N'Guessan, A. Lucie; Long, Philip E.; Hubbard, Susan S.; Banfield, Jillian F.

    2009-08-05

    Understanding how microorganisms alter their physical and chemical environment during bioremediation is hindered by our inability to resolve subsurface microbial activity with high spatial resolution. Here we demonstrate the use of a minimally invasive geophysical technique to monitor stimulated microbial activity during acetate amendment in an aquifer near Rifle, Colorado. During electrical induced polarization (IP) measurements, spatiotemporal variations in the phase response between imposed electric current and the resultant electric field correlated with changes in groundwater geochemistry accompanying stimulated iron and sulfate reduction and sulfide mineral precipitation. The magnitude of the phase response varied with measurement frequency (0.125 and 1 Hz) andwasdependent upon the dominant metabolic process. The spectral effect was corroborated using a biostimulated column experiment containing Rifle sediments and groundwater. Fluids and sediments recovered from regions exhibiting an anomalous phase response were enriched in Fe(II), dissolved sulfide, and cell-associated FeS nanoparticles. The accumulation of mineral precipitates and electroactive ions altered the ability of pore fluids to conduct electrical charge, accounting for the anomalous IP response and revealing the usefulness of multifrequency IP measurements for monitoring mineralogical and geochemical changes accompanying stimulated subsurface bioremediation.

  2. Sulfur isotope fractionation as an early indicator of microbial sulfate reduction under conditions of stimulated subsurface metal bioremediation

    NASA Astrophysics Data System (ADS)

    Druhan, J. L.; Conrad, M. E.; Williams, K. H.; Steefel, C.; Depaolo, D. J.

    2010-12-01

    Sustained in situ metal remediation presents a challenge in quantifying the onset, extent and overlap of each major chemical transition, as well as the evolution of physical, chemical and microbial parameters over multiple amendments. These parameters define a biogeochemically dynamic system requiring numerical reactive transport modeling to accurately predict cumulative contaminant stabilization. The use of novel monitoring tools to improve input parameters for numerical models is an essential component of the remediation strategy. Here we present aqueous geochemical data from three consecutive years of amended uranium bioremediation in a single well gallery from the US Department of Energy’s Environmental Remediation Science Program field site in Rifle, Colorado. Uranium bioremediation at the Rifle site is achieved through introduction of acetate at mM concentrations to stimulate first ferric iron reducers and subsequently sulfate reducers both naturally occurring in the aquifer. The factors controlling the onset of sulfate reduction and the extent to which iron and sulfate reduction can proceed concurrently are not well understood, and the initiation of sulfate reducing bacteria (SRB) activity must be closely monitored through aqueous geochemical data. Average background sulfate concentration in the aquifer is 9.6 mM with a 2σ standard deviation of 2.3, meaning that a 25% decrease in sulfate is necessary in order to identify sulfate reduction beyond background variation. Detection of aqueous sulfide should provide a more sensitive indicator of sulfate reduction, but the presence of ferrous iron in solution precipitates sulfides from the aqueous phase, causing a decline in measured sulfide concentrations and a lag in the onset of measurable sulfides up to 18 days after sulfate concentrations decrease. Sulfur isotopes present a means of overcoming this limitation. SRB fractionation factors are >10‰ even in open systems, meaning a 10% decrease in sulfate

  3. Letter report: Ari Patrinos -- Subsurface bioremediation

    SciTech Connect

    Happer, W.; MacDonald, G.J.; Ruderman, M.A.; Treiman, S.B.

    1995-07-26

    During the past summer, the authors had the opportunity to examine aspects of the remediation program of the Department of Energy (DOE). The most important conclusion that they have come to is that there is an urgent need to mount a comprehensive research program in remediation. It is also clear to them that DOE does not have the funding to carry out a program on the scale that is required. On the other hand, Environmental Management could very well fund such activities. They would hope that in the future there would be close collaboration between Environmental Management and Energy Research in putting together a comprehensive and well thought-out research program. Here, the authors comment on one aspect of remediation: subsurface bioremediation.

  4. In situ bioremediation of contaminated unsaturated subsurface soils

    SciTech Connect

    Sims, J.L.; Sims, R.C.; Dupont, R.R.; Matthews, J.E.; Russell, H.H.

    1993-05-01

    An emerging technology for the remediation of unsaturated subsurface soils involves the use of microorganisms to degrade contaminants which are present in such soils. Understanding the processes which drive in situ bioremediation, as well as the effectiveness and efficiency of the utilization of these systems, are issues which have been identified by the Regional Superfund Engineering Forum as concerns of Superfund decision makers. Although in situ bioremediation has been used for a number of years in the restoration of ground water contaminated by petroleum hydrocarbons, it has only been in recent years that in situ systems have been directed toward contaminants in unsaturated subsurface soils. Research has contributed greatly to understanding the biotic, chemical, and hydrologic parameters which contribute to or restrict the application of in-situ bioremediation and has been successful at a number of locations in demonstrating its effectiveness at field scale.

  5. ENGINEERING ISSUE: IN SITU BIOREMEDIATION OF CONTAMINATED UNSATURATED SUBSURFACE SOILS

    EPA Science Inventory

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

  6. Hydraulic control for manipulating subsurface conditions for in situ experiments of uranium(VI) bioremediation

    NASA Astrophysics Data System (ADS)

    Kitanidis, P.; Luo, J.; Wu, W.; Carley, J.; Mehlhorn, T.; Watson, D.; Criddle, C.; Jardine, P.

    2007-12-01

    A field test on in-situ subsurface bioremediation of uranium (VI) is underway at the Y-12 National Security Complex in the Oak Ridge Reservation, Oak Ridge, TN. A four-well system, including two downgradient extraction and two upgradient injection wells were installed to create an inner cell, which functioned as the treatment zone, nested within an outer cell, which protected the inner cell from the influence of regional flow. The proposed four- well system has several advantages in the subsurface flow field manipulation: (1) the recirculation ratio within the nested inner cell is less sensitive to the regional flow direction; (2) a transitional recirculation zone between the inner and outer cells can capture flow leakage from the inner cell, minimizing the release of untreated contaminants; (3) the size of the recirculation zone and residence times can be better controlled within the inner cell by changing the pumping rates. A three-phase remediation strategy was applied in this experiment. It included first removing nitrate prior to stimulation of U(VI) reduction, then adjusting the pH to levels favorable for activity of U(VI)-reducing bacteria, i.e., to about neutral values, and finally adding electron donor to the in-situ reactor to foster reduction and immobilization of U(VI). Tracer tests and bioremediation experiments demonstrated that the designed multiple-well system and the experimental strategy were successful in creating favorable subsurface chemical and biological conditions for uranium bioremediation.

  7. Augmented In Situ Subsurface Bioremediation Process™BIO-REM, Inc. - Demonstration Bulletin

    EPA Science Inventory

    The Augmented In Situ Subsurface Bioremediation Process™ developed by BIO-REM, Inc., uses microaerophilic bacteria and micronutrients (H-10) and surface tension depressants/penetrants for the treatment of hydrocarbon contaminated soils and groundwater. The bacteria utilize hydroc...

  8. Bioremediation of subsurface sediment and groundwater contaminated with pyridine and pyridine derivatives

    SciTech Connect

    Ronen, Z.

    1992-01-01

    The presence of toxic organic chemicals such as pyridine and its alkyl derivatives, found in groundwater as a consequence of industrial activities, present a direct hazard to human health and to the environment. The toxicity of these compounds, their teratogenic properties, and their irritating odor require urgent remediation. Physical, chemical, and biological treatments are commonly applied for the removal of organic pollutants from groundwater. In this investigation, the potential of a biological treatment was evaluated for the clean-up of subsurface and groundwater contaminated with pyridine and its alkyl derivatives. A pyridine-degrading denitrifying bacterium, an Alcaligenes sp., isolated from a polluted aquifer, successfully mineralized pyridine in the subsurface sediment under anaerobic conditions. Moreover, the isolated bacterium was much more effective, when compared to chemical treatment (Fenton's reagent), in mineralizing pyridine in the groundwater and subsurface sediments. In contrast to pyridine, alkylpyridines were not degraded under anaerobic conditions. However, under aerobic conditions indigenous bacteria were able to degrade all investigated contaminants. Thus, oxygen was the limiting factor for biodegradation of alkylpyridines. Degradation of these compounds also occurred in soil columns. In addition, a mixed culture capable of degrading 14 different alkylpyridine isomers was selected from the sediment and appeared to be very effective in removing pollutants from groundwater. Characterization of the different bacteria showed that all strains were gram-negative rods. The above findings suggest that bioremediation of pyridine-contaminated groundwater is feasible. Bioremediation may be in situ using either inoculation of the subsurface with pyridine-degrading bacteria or stimulation of native microorganisms.

  9. Electrode-based approach for monitoring in situ microbial activity during subsurface bioremediation

    SciTech Connect

    Williams, Kenneth H.; Nevin, Kelly P.; Franks, Ashley; Englert, Andreas L.; Long, Philip E.; Lovley, Derek R.

    2010-01-01

    Current production by microorganisms colonizing subsurface electrodes and its relationship to substrate availability and microbial activity was evaluated in an aquifer undergoing bioremediation. Borehole graphite anodes were installed downgradient from a region of acetate injection designed to stimulate bioreduction of U(VI); cathodes consisted of graphite electrodes embedded at the ground surface. Significant increases in current density (≤50 mA/m2) tracked delivery of acetate to the electrodes, dropping rapidly when acetate inputs were discontinued. An upgradient control produced low, steady currents (≤0.2 mA/m2). Elevated current was strongly correlated with uranium removal but minimal correlation existed with elevated Fe(II). Confocal laser scanning microscopy of electrodes revealed firmly attached biofilms, and analysis of 16S rRNA gene sequences indicated the electrode surfaces were dominated (67-80%) by Geobacter species. These results suggest that oxidation of acetate coupled to electron transfer to electrodes by Geobacter species was the primary source of current. This is the first demonstration that electrodes can produce readily detectable currents despite long-range (6 m) separation of anode and cathode and that current levels are likely related to rates of subsurface metabolism. It is expected that current production may serve as an effective proxy for monitoring in situ microbial activity in a variety of subsurface anoxic environments.

  10. An Electrode-based approach for monitoring in situ microbial activity during subsurface bioremediation

    SciTech Connect

    Williams, K.H.; Nevin, K.P.; Franks, A.; Englert, A.; Long, P.E.; Lovley, D.R.

    2009-11-15

    Current production by microorganisms colonizing subsurface electrodes and its relationship to substrate availability and microbial activity was evaluated in an aquifer undergoing bioremediation. Borehole graphite anodes were installed downgradient from a region of acetate injection designed to stimulate bioreduction of U(VI); cathodes consisted of graphite electrodes embedded at the ground surface. Significant increases in current density ({<=}50 mA/m{sup 2}) tracked delivery of acetate to the electrodes, dropping rapidly when acetate inputs were discontinued. An upgradient control electrode not exposed to acetate produced low, steady currents ({<=}0.2 mA/m{sup 2}). Elevated current was strongly correlated with uranium removal but minimal correlation existed with elevated Fe(II). Confocal laser scanning microscopy of electrodes revealed firmly attached biofilms, and analysis of 16S rRNA gene sequences indicated the electrode surfaces were dominated (67-80%) by Geobacter species. This is the first demonstration that electrodes can produce readily detectable currents despite long-range (6 m) separation of anode and cathode, and these results suggest that oxidation of acetate coupled to electron transfer to electrodes by Geobacter species was the primary source of current. Thus it is expected that current production may serve as an effective proxy for monitoring in situ microbial activity in a variety of subsurface anoxic environments.

  11. Residues of endosulfan in surface and subsurface agricultural soil and its bioremediation.

    PubMed

    Odukkathil, Greeshma; Vasudevan, Namasivayam

    2016-01-01

    The persistence of many hydrophobic pesticides has been reported by various workers in various soil environments and its bioremediation is a major concern due to less bioavailability. In the present study, the pesticide residues in the surface and subsurface soil in an area of intense agricultural activity in Pakkam Village of Thiruvallur District, Tamilnadu, India, and its bioremediation using a novel bacterial consortium was investigated. Surface (0-15 cm) and subsurface soils (15-30 cm and 30-40 cm) were sampled, and pesticides in different layers of the soil were analyzed. Alpha endosulfan and beta endosulfan concentrations ranged from 1.42 to 3.4 mg/g and 1.28-3.1 mg/g in the surface soil, 0.6-1.4 mg/g and 0.3-0.6 mg/g in the subsurface soil (15-30 cm), and 0.9-1.5 mg/g and 0.34-1.3 mg/g in the subsurface soil (30-40 cm) respectively. Residues of other persistent pesticides were also detected in minor concentrations. These soil layers were subjected to bioremediation using a novel bacterial consortium under a simulated soil profile condition in a soil reactor. The complete removal of alpha and beta endosulfan was observed over 25 days. Residues of endosulfate were also detected during bioremediation, which was subsequently degraded on the 30th day. This study revealed the existence of endosulfan in the surface and subsurface soils and also proved that the removal of such a ubiquitous pesticide in the surface and subsurface environment can be achieved in the field by bioaugumenting a biosurfactant-producing bacterial consortium that degrades pesticides. PMID:26413801

  12. Enhanced bioremediation of subsurface contamination: Enzyme recruitment and redesign

    SciTech Connect

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

    1991-12-01

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

  13. SOLID OXYGEN SOURCE FOR BIOREMEDIATION IN SUBSURFACE SOILS

    EPA Science Inventory

    Sodium percarbonate was encapsulated in poly(vinylidene chloride) to determine its potential as a slow-release oxygen source for biodegradation of contaminan ts in subsurface soils. In laboratory studies under aqueous conditions, the encapsulated sodium percarbonate was estimate...

  14. SOLID OXYGEN SOURCE FOR BIOREMEDIATION IN SUBSURFACE SOILS

    EPA Science Inventory

    Sodium percarbonate was encapsulated in poly(vinylidene chloride) to determine its potential as a slow-release oxygen source for biodegradation of contaminants in subsurface soils. n laboratory studies under aqueous conditions, the encapsulated sodium percarborate was estimated t...

  15. Proteogenomic monitoring of Geobacter physiology during stimulated uranium bioremediation

    SciTech Connect

    Wilkins, Mike; Verberkmoes, Nathan C; Williams, Ken; Callister, Stephen J; Mouser, Paula J; Elifantz, Hila; N'Guessan, A. Lucie; Thomas, Brian; Nicora, Carrie D.; Shah, Manesh B; Abraham, Paul E; Lipton, Mary S; Lovley, Derek; Hettich, Robert {Bob} L; Long, Phil; Banfield, Jillian F.

    2009-01-01

    Implementation of uranium bioremediation requires methods to monitor the membership and activities of the subsurface microbial communities that are responsible for reduction of soluble U(VI) to insoluble U(IV). Here we report a proteomics-based approach to simultaneously document strain membership and microbial physiology of the dominant Geobacter community members during in situ acetate amendment of the U-contaminated Rifle, CO aquifer. Three planktonic Geobacter-dominated samples were obtained from two wells down-gradient of acetate addition. Over 2,500 proteins from each of these samples were identified by matching LC MS/MS spectra to peptides predicted from 7 isolate Geobacter genomes. Genome-specific peptides indicate early proliferation of multiple M21 and G. bemidjiensis like strains and later possible emergence of M21 and G. bemidjiensis like strains more closely related to G. lovleyi. Throughout biostimulation, the proteome is dominated by enzymes that convert acetate to acetyl-CoA and pyruvate for central metabolism while abundant peptides matching TCA cycle proteins and ATP synthase subunits were also detected, indicating the importance of energy generation during the period of rapid growth following the start of biostimulation. Evolving Geobacter strain composition may be linked to changes in protein abundance over the course of biostimulation and may reflect changes in metabolic functioning. Thus, metagenomics independent community proteogenomics can be used to diagnose the status of the subsurface consortia upon which remediation biotechnology relies.

  16. Proteogenomic monitoring of Geobacter physiology during stimulated uranium bioremediation

    SciTech Connect

    Wilkins, Michael J.; VerBerkmoes, Nathan C.; Williams, Kenneth H.; Callister, Stephen J.; Mouser, Paula; Elifantz, H.; N'Guessan, A. Lucie; Thomas, Brian C.; Nicora, Carrie D.; Shah, Manesh B.; Abraham, Paul; Lipton, Mary S.; Lovely, Derek R.; Hettich, Robert L.; Long, Philip E.; Banfield, Jillian F.

    2009-10-01

    Implementation of uranium bioremediation requires methods to monitor the membership and activities of the subsurface microbial communities that are responsible for reduction of soluble U(VI) to insoluble U(IV). Here we report a proteomics-based approach to simultaneously document strain membership and microbial physiology of the dominant Geobacter community members during in situ acetate amendment of the U-contaminated Rifle, CO aquifer. Three planktonic Geobacter-dominated samples were obtained from two wells down-gradient of acetate addition. Over 2,500 proteins from each of these samples were identified by matching LC MS/MS spectra to peptides predicted from 7 isolate Geobacter genomes. Genome-specific peptides indicate early proliferation of multiple M21 and G. bemidjiensis–like strains and later possible emergence of M21 and G. bemidjiensis–like strains more closely related to G. lovleyi. Throughout biostimulation, the proteome is dominated by enzymes that convert acetate to acetyl-CoA and pyruvate for central metabolism while abundant peptides matching TCA cycle proteins and ATP synthase subunits were also detected, indicating the importance of energy generation during the period of rapid growth following the start of biostimulation. Evolving Geobacter strain composition may be linked to changes in protein abundance over the course of biostimulation and may reflect changes in metabolic functioning. Thus, metagenomics independent community proteogenomics can be used to diagnose the status of the subsurface consortia upon which remediation biotechnology relies.

  17. Proteogenomic monitoring of Geobacter physiology during stimulated uranium bioremediation

    SciTech Connect

    Wilkins, M.J.; VerBerkmoes, N.C.; Williams, K.H.; Callister, S.J.; Mouser, P.J.; Elifantz, H.; N'Guessan, A.L.; Thomas, B.C.; Nicora, C.D.; Shah, M.B.; Lipton, M.S.; Lovley, D.R.; Hettich, R.L.; Long, P.E.; Banfield, J.F.; Abraham, P.

    2009-08-01

    Implementation of uranium bioremediation requires methods for monitoring the membership and activities of the subsurface microbial communities that are responsible for reduction of soluble U(VI) to insoluble U(IV). Here, we report a proteomics-based approach for simultaneously documenting the strain membership and microbial physiology of the dominant Geobacter community members during in situ acetate amendment of the U-contaminated Rifle, CO, aquifer. Three planktonic Geobacter-dominated samples were obtained from two wells down-gradient of acetate addition. Over 2,500 proteins from each of these samples were identified by matching liquid chromatography-tandem mass spectrometry spectra to peptides predicted from seven isolate Geobacter genomes. Genome-specific peptides indicate early proliferation of multiple M21 and Geobacter bemidjiensis-like strains and later possible emergence of M21 and G. bemidjiensis-like strains more closely related to Geobacter lovleyi. Throughout biostimulation, the proteome is dominated by enzymes that convert acetate to acetyl-coenzyme A and pyruvate for central metabolism, while abundant peptides matching tricarboxylic acid cycle proteins and ATP synthase subunits were also detected, indicating the importance of energy generation during the period of rapid growth following the start of biostimulation. Evolving Geobacter strain composition may be linked to changes in protein abundance over the course of biostimulation and may reflect changes in metabolic functioning. Thus, metagenomics-independent community proteogenomics can be used to diagnose the status of the subsurface consortia upon which remediation biotechnology relies.

  18. Stimulating sediment bioremediation with benthic microbial fuel cells.

    PubMed

    Li, Wen-Wei; Yu, Han-Qing

    2015-01-01

    Efficient and sustainable technologies for cleaning up of contaminated sediments are under urgent demand. Bioremediation by utilizing the natural metabolic activities of sediment-inhabited microorganisms has been widely accepted as a viable option, but the relatively low efficiency and poor controllability severely limite its application. Here, we bring out the concept that electrochemical approaches may be used as an efficient means to stimulate sediment bioremediation. Although still at the very beginning, benthic microbial fuel cells (BMFC) as a remediation technology show many potential benefits, such as accelerated decontamination, self-sustained operation, relatively easy deployment and control, and environmental benignity. The unique features of BMFC setup and operation also give rise to substantially different challenges compared to conventional MFCs. In this review, we present a critical overview on the characteristics, possible application niches, and state-of-the-art progress of this technology. Especially, the current limitations in respect of system design, electrode selection, microbial control and selection of deployment environment are discussed in details, and the needed future research endeavors to promote its practical application are highlighted. PMID:25560929

  19. Performance Indicators for Uranium Bioremediation in the Subsurface: Basis and Assessment

    SciTech Connect

    Long, Philip E.; Yabusaki, Steven B.

    2006-12-29

    The purpose of this letter report is to identify performance indicators for in situ engineered bioremediation of subsurface uranium (U) contamination. This report focuses on in situ treatment of groundwater by biostimulation of extant in situ microbial populations (see http://128.3.7.51/NABIR/generalinfo/primers_guides/03_NABIR_primer.pdf for background information on bioremediation of metals and radionuclides). The treatment process involves amendment of the subsurface with an electron donor such as acetate, lactate, ethanol or other organic compound such that in situ microorganisms mediate the reduction of U(VI) to U(IV). U(VI) precipitates as uraninite or other insoluble U phase. Uranium is thus immobilized in place by such processes and is subject to reoxidation that may remobilize the reduced uranium. Related processes include augmenting the extant subsurface microbial populations, addition of electron acceptors, and introduction of chemically reducing materials such as zero-valent Fe. While metrics for such processes may be similar to those for in situ biostimulation, these related processes are not directly in the scope of this letter report.

  20. Subsurface interactions of actinide species and microorganisms : implications for the bioremediation of actinide-organic mixtures.

    SciTech Connect

    Banaszak, J.E.; Reed, D.T.; Rittmann, B.E.

    1999-02-12

    By reviewing how microorganisms interact with actinides in subsurface environments, we assess how bioremediation controls the fate of actinides. Actinides often are co-contaminants with strong organic chelators, chlorinated solvents, and fuel hydrocarbons. Bioremediation can immobilize the actinides, biodegrade the co-contaminants, or both. Actinides at the IV oxidation state are the least soluble, and microorganisms accelerate precipitation by altering the actinide's oxidation state or its speciation. We describe how microorganisms directly oxidize or reduce actinides and how microbiological reactions that biodegrade strong organic chelators, alter the pH, and consume or produce precipitating anions strongly affect actinide speciation and, therefore, mobility. We explain why inhibition caused by chemical or radiolytic toxicities uniquely affects microbial reactions. Due to the complex interactions of the microbiological and chemical phenomena, mathematical modeling is an essential tool for research on and application of bioremediation involving co-contamination with actinides. We describe the development of mathematical models that link microbiological and geochemical reactions. Throughout, we identify the key research needs.

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

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

    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

  2. Methane production from protozoan endosymbionts following stimulation of microbial metabolism within subsurface sediments

    PubMed Central

    Holmes, Dawn E.; Giloteaux, Ludovic; Orellana, Roberto; Williams, Kenneth H.; Robbins, Mark J.; Lovley, Derek R.

    2014-01-01

    Previous studies have suggested that protozoa prey on Fe(III)- and sulfate-reducing bacteria that are enriched when acetate is added to uranium contaminated subsurface sediments to stimulate U(VI) reduction. In order to determine whether protozoa continue to impact subsurface biogeochemistry after these acetate amendments have stopped, 18S rRNA and ß-tubulin sequences from this phase of an in situ uranium bioremediation field experiment were analyzed. Sequences most similar to Metopus species predominated, with the majority of sequences most closely related to M. palaeformis, a cilitated protozoan known to harbor methanogenic symbionts. Quantification of mcrA mRNA transcripts in the groundwater suggested that methanogens closely related to Metopus endosymbionts were metabolically active at this time. There was a strong correlation between the number of mcrA transcripts from the putative endosymbiotic methanogen and Metopus ß-tubulin mRNA transcripts during the course of the field experiment, suggesting that the activity of the methanogens was dependent upon the activity of the Metopus species. Addition of the eukaryotic inhibitors cyclohexamide and colchicine to laboratory incubations of acetate-amended subsurface sediments significantly inhibited methane production and there was a direct correlation between methane concentration and Metopus ß-tubulin and putative symbiont mcrA gene copies. These results suggest that, following the stimulation of subsurface microbial growth with acetate, protozoa harboring methanogenic endosymbionts become important members of the microbial community, feeding on moribund biomass and producing methane. PMID:25147543

  3. BIOREMEDIATION

    EPA Science Inventory

    Bioremediation is a method for using the activities of microorganisms and-or plants to transform organic or inorganic compounds that may be harmful to humans, animals, plants or the environment to compounds that are less harmful. In many instances the toxic compounds may be compl...

  4. A biogeochemical framework for bioremediation of plutonium(V) in the subsurface environment.

    PubMed

    Deo, Randhir P; Rittmann, Bruce E

    2012-07-01

    Accidental release of plutonium (Pu) from storage facilities in the subsurface environment is a concern for the safety of human beings and the environment. Given the complexity of the subsurface environment and multivalent state of Pu, we developed a quantitative biogeochemical framework for bioremediation of Pu(V)O(2) (+) in the subsurface environment. We implemented the framework in the biogeochemical model CCBATCH by expanding its chemical equilibrium for aqueous complexation of Pu and its biological sub-models for including Pu's toxicity and reduction reactions. The quantified framework reveals that most of the Pu(V) is speciated as free Pu(V)O(2) (+) ((aq)), which is a problem if the concentration of free Pu(V)O(2) (+) is ≥28 μM (the half-maximum toxicity value for bacteria able to reduce Pu(V) to Pu(III)PO(4(am))) or ≥250 μM (the full-toxicity value that takes the bioreduction rate to zero). The framework includes bioreduction of Fe(3+) to Fe(2+), which abiotically reduces Pu(V)O(2) (+) to Pu(IV) and then to Pu(III). Biotic (enzymatic) reduction of Pu(V)O(2) (+) directly to Pu(III) by Shewanella alga (S. alga) is also included in the framework. Modeling results also reveal that for formation of Pu(III)PO(4(am)), the desired immobile product, the concentration of coexisting model strong ligand-nitrilotriacetic acid (NTA)-should be less than or equal to the concentration of total Pu(III). PMID:22209805

  5. Electrodic voltages accompanying stimulated bioremediation of a uranium-contaminated aquifer

    SciTech Connect

    Williams, K.H.; N'Guessan, A.L.; Druhan, J.; Long, P.E.; Hubbard, S.S.; Lovley, D.R.; Banfield, J.F.

    2009-11-15

    The inability to track the products of subsurface microbial activity during stimulated bioremediation has limited its implementation. We used spatiotemporal changes in electrodic potentials (EP) to track the onset and persistence of stimulated sulfate-reducing bacteria in a uranium-contaminated aquifer undergoing acetate amendment. Following acetate injection, anomalous voltages approaching -900 mV were measured between copper electrodes within the aquifer sediments and a single reference electrode at the ground surface. Onset of EP anomalies correlated in time with both the accumulation of dissolved sulfide and the removal of uranium from groundwater. The anomalies persisted for 45 days after halting acetate injection. Current-voltage and current-power relationships between measurement and reference electrodes exhibited a galvanic response, with a maximum power density of 10 mW/m{sup 2} during sulfate reduction. We infer that the EP anomalies resulted from electrochemical differences between geochemically reduced regions and areas having higher oxidation potential. Following the period of sulfate reduction, EP values ranged from -500 to -600 mV and were associated with elevated concentrations of ferrous iron. Within 10 days of the voltage decrease, uranium concentrations rebounded from 0.2 to 0.8 {mu}M, a level still below the background value of 1.5 {mu}M. These findings demonstrate that EP measurements provide an inexpensive and minimally invasive means for monitoring the products of stimulated microbial activity within aquifer sediments and are capable of verifying maintenance of redox conditions favorable for the stability of bioreduced contaminants, such as uranium.

  6. New Technique for Speciation of Uranium in Sediments Following Acetate-Stimulated Bioremediation

    SciTech Connect

    Not Available

    2011-06-22

    Acetate-stimulated bioremediation is a promising new technique for sequestering toxic uranium contamination from groundwater. The speciation of uranium in sediments after such bioremediation attempts remains unknown as a result of low uranium concentration, and is important to analyzing the stability of sequestered uranium. A new technique was developed for investigating the oxidation state and local molecular structure of uranium from field site sediments using X-Ray Absorption Spectroscopy (XAS), and was implemented at the site of a former uranium mill in Rifle, CO. Glass columns filled with bioactive Rifle sediments were deployed in wells in the contaminated Rifle aquifer and amended with a hexavalent uranium (U(VI)) stock solution to increase uranium concentration while maintaining field conditions. This sediment was harvested and XAS was utilized to analyze the oxidation state and local molecular structure of the uranium in sediment samples. Extended X-Ray Absorption Fine Structure (EXAFS) data was collected and compared to known uranium spectra to determine the local molecular structure of the uranium in the sediment. Fitting was used to determine that the field site sediments did not contain uraninite (UO{sub 2}), indicating that models based on bioreduction using pure bacterial cultures are not accurate for bioremediation in the field. Stability tests on the monomeric tetravalent uranium (U(IV)) produced by bioremediation are needed in order to assess the efficacy of acetate-stimulation bioremediation.

  7. MICROBIAL ACTIVITY IN SUBSURFACE SAMPLES BEFORE AND DURING NITRATE-ENHANCED BIOREMEDIATION

    EPA Science Inventory

    A study was conducted to determine the microbial activity of a site contaminated with JP-4 jet fuel, before and during nitrate-enhanced bioremediation. amples at three depths from six different locations were collected aseptically under anaerobic conditions before and during trea...

  8. Fate of N and P sources in subsurfaces during in-situ bioremediation

    SciTech Connect

    Amery, J.H.A.; Bajpai, R.K.; Zappi, M.E.

    1995-12-31

    Limitations of macronutrients and electron acceptors are considered primary reasons why a number of otherwise easily biodegradable chemicals persist in nature even in presence of microbial flora capable of metabolizing them. In this research, interactions of a number of macronutrients (nitrogen and phosphorous sources) with several different soils have been investigated. Both sorptive as well as biotic and abiotic transformations have been studied. The experimental results and their interpretations will be discussed in this presentation. Quantification of these interactions is expected to lead to a more methodical selection of the appropriate macronutrients and their doses for in-situ Bioremediation.

  9. Hydrodynamics of foam flows for in situ bioremediation of DNAPL-contaminated subsurface

    SciTech Connect

    Bouillard, J.X.; Enzien, M.; Peters, R.W.; Frank, J.; Botto, R.E.; Cody, G.

    1995-12-31

    In situ remediation technologies such as (1) pump-and-treat, (2) soil vacuum extraction, (3) soil flushing/washing, and (4) bioremediation are being promoted for cleanup of contaminated sites. However, these technologies are limited by flow channeling of chemical treatment agents. Argonne National Laboratory (ANL), the Gas Research Institute, and the Institute of Gas Technology are collaboratively investigating a new bioremediation technology using foams. The ability of a foam to block pores and limit flow bypassing makes it ideal for DNAPL remediation. The hydrodynamics of gas/liquid foam flows differ significantly from the hydrodynamics of single and multiphase nonfoaming flows. This is illustrated using a multiphase flow hydrodynamic computer model and a two-dimensional flow visualization cell. A state-of-the-art, nonintrusive, three-dimensional magnetic resonance imaging technique was developed to visualize DNAPL mobilization in three dimensions. Mechanisms to be investigated are in situ DNAPL interactions with the foam, DNAPL emulsification, DNAPL scouring by the foam, and subsequent DNAPL mobilization/redeposition in the porous media.

  10. The Stimulation of Hydrocarbon Reservoirs with Subsurface Nuclear Explosions

    SciTech Connect

    LORENZ,JOHN C.

    2000-12-08

    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.

  11. Evaluation of inoculum addition to stimulate in situ bioremediation of oily-sludge-contaminated soil.

    PubMed

    Mishra, S; Jyot, J; Kuhad, R C; Lal, B

    2001-04-01

    A full-scale study evaluating an inoculum addition to stimulate in situ bioremediation of oily-sludge-contaminated soil was conducted at an oil refinery where the indigenous population of hydrocarbon-degrading bacteria in the soil was very low (10(3) to 10(4) CFU/g of soil). A feasibility study was conducted prior to the full-scale bioremediation study. In this feasibility study, out of six treatments, the application of a bacterial consortium and nutrients resulted in maximum biodegradation of total petroleum hydrocarbon (TPH) in 120 days. Therefore, this treatment was selected for the full-scale study. In the full-scale study, plots A and B were treated with a bacterial consortium and nutrients, which resulted in 92.0 and 89.7% removal of TPH, respectively, in 1 year, compared to 14.0% removal of TPH in the control plot C. In plot A, the alkane fraction of TPH was reduced by 94.2%, the aromatic fraction of TPH was reduced by 91.9%, and NSO (nitrogen-, sulfur-, and oxygen-containing compound) and asphaltene fractions of TPH were reduced by 85.2% in 1 year. Similarly, in plot B the degradation of alkane, aromatic, and NSO plus asphaltene fractions of TPH was 95.1, 94.8, and 63.5%, respectively, in 345 days. However, in plot C, removal of alkane (17.3%), aromatic (12.9%), and NSO plus asphaltene (5.8%) fractions was much less. The population of introduced Acinetobacter baumannii strains in plots A and B was stable even after 1 year. Physical and chemical properties of the soil at the bioremediation site improved significantly in 1 year. PMID:11282620

  12. Evaluation of Inoculum Addition To Stimulate In Situ Bioremediation of Oily-Sludge-Contaminated Soil

    PubMed Central

    Mishra, Sanjeet; Jyot, Jeevan; Kuhad, Ramesh C.; Lal, Banwari

    2001-01-01

    A full-scale study evaluating an inoculum addition to stimulate in situ bioremediation of oily-sludge-contaminated soil was conducted at an oil refinery where the indigenous population of hydrocarbon-degrading bacteria in the soil was very low (103 to 104 CFU/g of soil). A feasibility study was conducted prior to the full-scale bioremediation study. In this feasibility study, out of six treatments, the application of a bacterial consortium and nutrients resulted in maximum biodegradation of total petroleum hydrocarbon (TPH) in 120 days. Therefore, this treatment was selected for the full-scale study. In the full-scale study, plots A and B were treated with a bacterial consortium and nutrients, which resulted in 92.0 and 89.7% removal of TPH, respectively, in 1 year, compared to 14.0% removal of TPH in the control plot C. In plot A, the alkane fraction of TPH was reduced by 94.2%, the aromatic fraction of TPH was reduced by 91.9%, and NSO (nitrogen-, sulfur-, and oxygen-containing compound) and asphaltene fractions of TPH were reduced by 85.2% in 1 year. Similarly, in plot B the degradation of alkane, aromatic, and NSO plus asphaltene fractions of TPH was 95.1, 94.8, and 63.5%, respectively, in 345 days. However, in plot C, removal of alkane (17.3%), aromatic (12.9%), and NSO plus asphaltene (5.8%) fractions was much less. The population of introduced Acinetobacter baumannii strains in plots A and B was stable even after 1 year. Physical and chemical properties of the soil at the bioremediation site improved significantly in 1 year. PMID:11282620

  13. Natural attenuation and biosurfactant-stimulated bioremediation of estuarine sediments contaminated with diesel oil.

    PubMed

    Bayer, Débora M; Chagas-Spinelli, Alessandra C O; Gavazza, Sávia; Florencio, Lourdinha; Kato, Mario T

    2013-09-01

    We evaluated the bioremediation, by natural attenuation (NA) and by natural attenuation stimulated (SNA) using a rhamnolipid biosurfactant, of estuarine sediments contaminated with diesel oil. Sediment samples (30 cm) were put into 35 cm glass columns, and the concentrations of the 16 polycyclic aromatic hydrocarbons (PAHs) prioritized by the US Environmental Protection Agency were monitored for 111 days. Naphthalene percolated through the columns more than the other PAHs, and, in general, the concentrations of the lower molecular weight PAHs, consisting of two and three aromatic rings, changed during the first 45 days of treatment, whereas the concentrations of the higher molecular weight PAHs, consisting of four, five, and six rings, were more stable. The higher molecular weight PAHs became more available after 45 days, in the deeper parts of the columns (20-30 cm). Evidence of degradation was observed only for some compounds, such as pyrene, with a total removal efficiency of 82 and 78 % in the NA and SNA treatments, respectively, but without significant difference. In the case of total PAH removal, the efficiencies were significantly different of 82 and 67 %, respectively. PMID:23821292

  14. Cometabolic bioremediation

    SciTech Connect

    Hazen, Terry C.

    2009-02-15

    Cometabolic bioremediation is probably the most under appreciated bioremediation strategy currently available. Cometabolism strategies stimulate only indigenous microbes with the ability to degrade the contaminant and cosubstrate e.g. methane, propane, toluene and others. This highly targeted stimulation insures that only those microbes that can degrade the contaminant are targeted, thus reducing amendment costs, well and formation plugging, etc. Cometabolic bioremediation has been used on some of the most recalcitrant contaminants, e.g. PCE, TCE, MTBE, TNT, dioxane, atrazine, etc. Methanotrophs have been demonstrated to produce methane monooxygense, an oxidase that can degrade over 300 compounds. Cometabolic bioremediation also has the advantage of being able to degrade contaminants to trace concentrations, since the biodegrader is not dependent on the contaminant for carbon or energy. Increasingly we are finding that in order to protect human health and the environment that we must remediate to lower and lower concentrations, especially for compounds like endocrine disrupters, thus cometabolism may be the best and maybe the only possibility that we have to bioremediate some contaminants.

  15. Integration of pneumatic fracturing with bioremediation from the enhanced removal of BTX from low permeability gasoline-contaminated soils

    SciTech Connect

    Venkatraman, S.N.; Kosson, D.S.; Schuring, J.R.; Boland, T.M.

    1995-11-01

    A pilot-scale evaluation of the integrated pneumatic fracturing and bioremediation system was carried out to demonstrate the enhanced removal of BTX from a gasoline contaminated, low permeability soil formation. The fracturing enhanced subsurface permeability by an average of over 36 times, and established an extended bioremediation zone supporting aerobic, denitrifying and methanogenic populations. Subsurface amendment injections consisting of phosphate and nitrogen were made periodically over a 50-week period to stimulate microbial activity. Results indicate that 79% of the soil-phase BTX was removed during the field test, with over 85% of the mass removed attributable to bioremediation.

  16. In-situ bioremediation via horizontal wells

    SciTech Connect

    Hazen, T.C.; Looney, B.B.; Enzien, M.; Franck, M.M.; Fliermans, C.B.; Eddy, C.A.

    1993-12-31

    This project is designed to demonstrate in situ bioremediation of groundwater and sediment contaminated with chlorinated solvents. Indigenous microorganisms were stimulated to degrade TCE, PCE and their daughter products in situ by addition of nutrients to the contaminated zone. In situ biodegradation is a highly attractive technology for remediation because contaminants are destroyed, not simply moved to another location or immobilized, thus decreasing costs, risks, and time, while increasing efficiency and public and regulatory acceptability. Bioremediation has been found to be among the least costly technologies in applications where it will work (Radian 1989). Subsurface soils and water adjacent to an abandoned process sewer line at the SRS have been found to have elevated levels of TCE (Marine and Bledsoe 1984). This area of subsurface and groundwater contamination is the focus of a current integrated demonstration of new remediation technologies utilizing horizontal wells. Bioremediation has the potential to enhance the performance of in situ air stripping as well as offering stand-alone remediation of this and other contaminated sites (Looney et al. 1991). Horizontal wells could also be used to enhance the recovery of groundwater contaminants for bioreactor conversions from deep or inaccessible areas (e.g., under buildings) and to enhance the distribution of nutrient or microbe additions in an in situ bioremediation.

  17. Bioremediation of nitrates and carbon tetrachloride in groundwater

    SciTech Connect

    Brouns, T.M.

    1993-01-01

    A development and demonstration program is presently underway to test an in situ bioremediation technology for treating nitrates and carbon tetrachloride in contaminated Hanford groundwaters. Several key technical issues have prevented widespread use of bioremediation for cleanup of organic and inorganic subsurface contaminants, including the development of adequate nutrient delivery systems; effective mixing technologies for contacting microorganisms, nutrients, and contaminants; methods to control biofouling or excessive microbial growth; and adequate tools for designing, predicting, and monitoring the performance of in situ technologies in heterogeneous subsurface environments. The goal of this program is to address these technical issues in an integrated laboratory-, bench-, and field-scale demonstration by stimulating native microorganisms and accelerating the natural degradation of NO{sub 3}{sup {minus}} CCl{sub 4} and chloroform.

  18. Bioremediation of nitrates and carbon tetrachloride in groundwater

    SciTech Connect

    Brouns, T.M.

    1993-01-01

    A development and demonstration program is presently underway to test an in situ bioremediation technology for treating nitrates and carbon tetrachloride in contaminated Hanford groundwaters. Several key technical issues have prevented widespread use of bioremediation for cleanup of organic and inorganic subsurface contaminants, including the development of adequate nutrient delivery systems; effective mixing technologies for contacting microorganisms, nutrients, and contaminants; methods to control biofouling or excessive microbial growth; and adequate tools for designing, predicting, and monitoring the performance of in situ technologies in heterogeneous subsurface environments. The goal of this program is to address these technical issues in an integrated laboratory-, bench-, and field-scale demonstration by stimulating native microorganisms and accelerating the natural degradation of NO[sub 3][sup [minus

  19. Monitoring and interpreting bioremediation effectiveness

    SciTech Connect

    Bragg, J.R.; Prince, R.C.; Harner, J.; Atlas, R.M.

    1993-12-31

    Following the Exxon Valdez oil spill in 1989, extensive research was conducted by the US Environments Protection Agency and Exxon to develop and implement bioremediation techniques for oil spill cleanup. A key challenge of this program was to develop effective methods for monitoring and interpreting bioremediation effectiveness on extremely heterogenous intertidal shorelines. Fertilizers were applied to shorelines at concentrations known to be safe, and effectiveness achieved in acceleration biodegradation of oil residues was measure using several techniques. This paper describes the most definitive method identified, which monitors biodegradation loss by measuring changes in ratios of hydrocarbons to hopane, a cycloalkane present in the oil that showed no measurable degradation. Rates of loss measured by the hopane ratio method have high levels of statistical confidence, and show that the fertilizer addition stimulated biodegradation rates as much a fivefold. Multiple regression analyses of data show that fertilizer addition of nitrogen in interstitial pore water per unit of oil load was the most important parameter affecting biodegradation rate, and results suggest that monitoring nitrogen concentrations in the subsurface pore water is preferred technique for determining fertilizer dosage and reapplication frequency.

  20. Metallic particles to stimulate sulfate reduction: A new approach for Bioremediation in low pH streams

    NASA Astrophysics Data System (ADS)

    Kumar, Naresh; Bastiaens, Leen; Vanbroekhoven, Karolien; Millot, Romain; Battaglia-Brunet, Fabienne; Diels, Ludo

    2010-05-01

    Extensive research has been carried out on efficiency of ZVI (Zero Valent Iron) and SRB (Sulfate Reducing Bacteria) for treatment of inorganics in contaminated groundwaters. ZVI is proved as a potential remediation agent due to multiple ZVI-metal interactions such as surface complexation, reduction and (co) precipitation. But little information is available till date on stability of precipitates, which is very important while dealing subsurface processes. SRB's are well known for metal removal and stable precipitates, but most of the time, the pH in mining areas are significantly low, which either restrict the stimulation of SRB or requires extra substrate and time. During anaerobic corrosion, ZVI deplete O2 and produce water derived H2, resulting an increase in pH and decrease in redox potential which makes it very efficient in low pH plumes. Moreover, SRB can potentially use this hydrogen as an electron donor to raise biomass yield significantly to accelerate reductive sulfate removal. The main objective of this research was to determine whether the combination of SRB and ZVI can improve the rate of contaminant removal and stability of precipitates. Within the framework of this study, we tested experimentally different parameters: concentration and particle size (ranging from 70 nm to 300 mm) of ZVI to stimulate sulfate reduction for subsequent removal of metals such as As, Cd and Zn in groundwaters and sediments with low pH (~3). Stability of precipitates was studied as well in flowthrough columns by changing pH and redox conditions. In our experiment, we find that ZVI is very efficient in stimulating sulfate reduction, fast removal of contaminants and more stable precipitates "This is a contribution of the AquaTRAIN MRTN (Contract No. MRTN-CT-2006-035420) funded under the European Commission Sixth Framework Programme (2002-2006) Marie Curie Actions, Human Resources & Mobility Activity Area - Research Training Networks"

  1. Numerical simulations in support of the in situ bioremediation demonstration at Savannah River

    SciTech Connect

    Travis, B.J.; Rosenberg, N.D.

    1994-06-01

    This report assesses the performance of the in situ bioremediation technology demonstrated at the Savannah River Integrated Demonstration (SRID) site in 1992--1993. The goal of the technology demonstration was to stimulate naturally occurring methanotrophic bacteria at the SRID site with injection of methane, air and air-phase nutrients (nitrogen and phosphate) such that significant amounts of the chlorinated solvent present in the subsurface would be degraded. Our approach is based on site-specific numerical simulations using the TRAMP computer code. In this report, we discuss the interactions among the physical and biochemical processes involved in in situ bioremediation. We also investigate improvements to technology performance, make predictions regarding the performance of this technology over long periods of time and at different sites, and compare in situ bioremediation with other remediation technologies.

  2. Design Of Bioremediation Systems For Groundwater (Aerobic and Anaerobic Plus Representative Case Studies)

    EPA Science Inventory

    The attached presentation discusses the fundamentals of bioremediation in the subsurface. The basics of aerobic, cometabolic, and anaerobic bioremediation are presented. Case studies from the Delaware Sand & Gravel Superfund Site, Dover Cometabolic Research Project and the SABR...

  3. Enhancing bioremediation

    SciTech Connect

    Koenigsberg, S.

    1997-02-01

    Oxygen is often the limiting factor in aerobic bioremediation. Without adequate oxygen, contaminant degradation will either cease or proceed by highly inefficient anaerobic processes. Researchers at Regenesis Bioremediation Products recently develope a technology to combat this problem, Oxygen Release Compound (ORC) a unique formulation of magnesium peroxide release oxygen slowly when hydrated. ORC is idea for supporting bioremediation of underground storage tank releases. ORC treatment represents a low intensity approach to remediation - simple, passive, low-cost, long term enhancement of a natural attenuation. 1 fig.

  4. Subsurface optical stimulation of the rat prostate nerves using continuous-wave near-infrared laser radiation

    NASA Astrophysics Data System (ADS)

    Tozburun, Serhat; Lagoda, Gwen A.; Burnett, Arthur L.; Fried, Nathaniel M.

    2012-02-01

    Successful identification and preservation of the cavernous nerves (CN), which are responsible for sexual function, during prostate cancer surgery, will require subsurface detection of the CN beneath a thin fascia layer. This study explores optical nerve stimulation (ONS) in the rat with a fascia layer placed over the CN. Two near-IR diode lasers (1455 nm and 1550 nm lasers) were used to stimulate the CN in CW mode with a 1-mm-diameter spot in 8 rats. The 1455 nm wavelength provides an optical penetration depth (OPD) of ~350 μm, while 1550 nm provides an OPD of ~1000 μm (~3 times deeper than 1455 nm and 1870 nm wavelengths previously tested). Fascia layers with thicknesses of 85 - 600 μm were placed over the CN. Successful ONS was confirmed by an intracavernous pressure (ICP) response in the rat penis at 1455 nm through fascia 110 μm thick and at 1550 nm through fascia 450 μm thick. Higher incident laser power was necessary and weaker and slower ICP responses were observed as fascia thickness was increased. Subsurface ONS of the rat CN at a depth of 450 μm using a 1550 nm laser is feasible.

  5. Bioremediation of contaminated groundwater

    SciTech Connect

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

    1992-12-31

    The present invention relates to a method for in situ bioremediation of contaminated soil and groundwater. In particular, the invention relates to remediation of contaminated soil and groundwater by the injection of nutrients to stimulate growth of pollutant-degrading microorganisms. The United States Government has rights in this invention pursuant to Contract No. DE-AC09-89SR18035 between the US Department of Energy and Westinghouse Savannah River Company.

  6. Numerical simulation of in situ bioremediation

    SciTech Connect

    Travis, B.J.

    1998-12-31

    Models that couple subsurface flow and transport with microbial processes are an important tool for assessing the effectiveness of bioremediation in field applications. A numerical algorithm is described that differs from previous in situ bioremediation models in that it includes: both vadose and groundwater zones, unsteady air and water flow, limited nutrients and airborne nutrients, toxicity, cometabolic kinetics, kinetic sorption, subgridscale averaging, pore clogging and protozoan grazing.

  7. Nitrogen Stimulates the Growth of Subsurface Basalt-associated Microorganisms at the Western Flank of the Mid-Atlantic Ridge

    PubMed Central

    Zhang, Xinxu; Fang, Jing; Bach, Wolfgang; Edwards, Katrina J.; Orcutt, Beth N.; Wang, Fengping

    2016-01-01

    Oceanic crust constitutes the largest aquifer system on Earth, and microbial activity in this environment has been inferred from various geochemical analyses. However, empirical documentation of microbial activity from subsurface basalts is still lacking, particularly in the cool (<25°C) regions of the crust, where are assumed to harbor active iron-oxidizing microbial communities. To test this hypothesis, we report the enrichment and isolation of crust-associated microorganisms from North Pond, a site of relatively young and cold basaltic basement on the western flank of the Mid-Atlantic Ridge that was sampled during Expedition 336 of the Integrated Ocean Drilling Program. Enrichment experiments with different carbon (bicarbonate, acetate, methane) and nitrogen (nitrate and ammonium) sources revealed significant cell growth (one magnitude higher cell abundance), higher intracellular DNA content, and increased Fe3+/ΣFe ratios only when nitrogen substrates were added. Furthermore, a Marinobacter strain with neutrophilic iron-oxidizing capabilities was isolated from the basalt. This work reveals that basalt-associated microorganisms at North Pond had the potential for activity and that microbial growth could be stimulated by in vitro nitrogen addition. Furthermore, iron oxidation is supported as an important process for microbial communities in subsurface basalts from young and cool ridge flank basement. PMID:27199959

  8. Nitrogen Stimulates the Growth of Subsurface Basalt-associated Microorganisms at the Western Flank of the Mid-Atlantic Ridge.

    PubMed

    Zhang, Xinxu; Fang, Jing; Bach, Wolfgang; Edwards, Katrina J; Orcutt, Beth N; Wang, Fengping

    2016-01-01

    Oceanic crust constitutes the largest aquifer system on Earth, and microbial activity in this environment has been inferred from various geochemical analyses. However, empirical documentation of microbial activity from subsurface basalts is still lacking, particularly in the cool (<25°C) regions of the crust, where are assumed to harbor active iron-oxidizing microbial communities. To test this hypothesis, we report the enrichment and isolation of crust-associated microorganisms from North Pond, a site of relatively young and cold basaltic basement on the western flank of the Mid-Atlantic Ridge that was sampled during Expedition 336 of the Integrated Ocean Drilling Program. Enrichment experiments with different carbon (bicarbonate, acetate, methane) and nitrogen (nitrate and ammonium) sources revealed significant cell growth (one magnitude higher cell abundance), higher intracellular DNA content, and increased Fe(3+)/ΣFe ratios only when nitrogen substrates were added. Furthermore, a Marinobacter strain with neutrophilic iron-oxidizing capabilities was isolated from the basalt. This work reveals that basalt-associated microorganisms at North Pond had the potential for activity and that microbial growth could be stimulated by in vitro nitrogen addition. Furthermore, iron oxidation is supported as an important process for microbial communities in subsurface basalts from young and cool ridge flank basement. PMID:27199959

  9. A case study of the intrinsic bioremediation of petroleum hydrocarbons

    SciTech Connect

    Barker, G.W.; Raterman, K.T.; Fisher, J.B.; Corgan, J.M.

    1995-12-31

    Condensate liquids have been found to contaminate soil and groundwater at two gas production sites in the Denver Basin operated by Amoco Production Co. These sites have been closely monitored since July 1993 to determine whether intrinsic aerobic or anaerobic bioremediation of hydrocarbons occurs at a sufficient rate and to an adequate endpoint to support a no-intervention decision. Groundwater monitoring and analysis of soil cores suggest that intrinsic bioremediation is occurring at these sites by multiple pathways including aerobic oxidation, Fe{sup 3+} reduction, and sulfate reduction. In laboratory experiments the addition of gas condensate hydrocarbons to saturated soil from the gas production site stimulated sulfate reduction under anaerobic and oxygen-limiting conditions, and nitrate and Fe{sup 3+} reduction under oxygen-limiting conditions, compared to biotic controls that lacked hydrocarbon and sterile controls. The sulfate reduction corresponded to a reduction in the amount of toluene relative to other hydrocarbons. These results confirmed that subsurface soils at the gas production site have the potential for intrinsic bioremediation of hydrocarbons.

  10. Bioremediation of contaminated groundwater

    DOEpatents

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

    1995-01-24

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

  11. Bioremediation of contaminated groundwater

    DOEpatents

    Hazen, Terry C.; Fliermans, Carl B.

    1995-01-01

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

  12. Bioremediation of contaminated groundwater

    DOEpatents

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

    1994-01-01

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

  13. Case study: Bioremediation in the Aleutian Islands

    SciTech Connect

    Steward, K.J.; Laford, H.D.

    1995-12-31

    This case study describes the design, construction, and operation of a bioremediation pile on Adak Island, which is located in the Aleutian Island chain. Approximately 1,900 m{sup 3} of petroleum-contaminated soil were placed in the bioremediation pile. The natural bioremediation process was enhanced by an oxygen and nutrient addition system to stimulate microbial activity. Despite the harsh weather on the island, after the first 6 months of operation, laboratory analyses of soil samples indicated a significant (80%) reduction in diesel concentrations.

  14. Laboratory studies of oil spill bioremediation; toward understanding field behavior

    SciTech Connect

    Prince, R.C.; Hinton, S.M.; Elmendorf, D.L.; Lute, J.R.; Grossman, M.J.; Robbins, W.K.; Hsu, Chang S.; Richard, B.E.; Haith, C.E.; Senius, J.D.; Minak-Bernero, V.; Chianelli, R.R.; Bragg, J.R.; Douglas, G.S.

    1993-12-31

    Oil spill remediation aims to enhance the natural process of microbial hydrocarbon biodegradation. The microbial foundations have been studied throughout this century, but the focus of most of this work has been on the degradation of well defined compounds by well defined microbial species. This paper addresses laboratory studies on crude oil biodegradation by microbial consortia obtained from oiled beaches in Prince William Sound, Alaska following the spill from the Exxon Valdez. It demonstrates that oil degradation is indeed likely to be nitrogen-limited in Prince William Sound, the different molecular classes in crude oil that are subjected to biodegradation, the identification of conserved species in the oil that can be used for assessing biodegradation and bioremediation in the field, the effectiveness of fertilizers in stimulating sub-surface biodegradation, the role of the olephilic fertilizer Inipol EAP22, and the identification of the oil-degrading microorganisms in Prince William Sound. Together, these laboratory studies provided guidance and important insights into the microbial phenomena underlying the successful bioremediation of the oiled shorelines.

  15. Treatment of a mud pit by bioremediation.

    PubMed

    Avdalović, Jelena; Đurić, Aleksandra; Miletić, Srdjan; Ilić, Mila; Milić, Jelena; Vrvić, Miroslav M

    2016-08-01

    The mud generated from oil and natural gas drilling, presents a considerable ecological problem. There are still insufficient remedies for the removal and minimization of these very stable emulsions. Existing technologies that are in use, more or less successfully, treat about 20% of generated waste drilling mud, while the rest is temporarily deposited in so-called mud pits. This study investigated in situ bioremediation of a mud pit. The bioremediation technology used in this case was based on the use of naturally occurring microorganisms, isolated from the contaminated site, which were capable of using the contaminating substances as nutrients. The bioremediation was stimulated through repeated inoculation with a zymogenous microbial consortium, along with mixing, watering and biostimulation. Application of these bioremediation techniques reduced the concentration of total petroleum hydrocarbons from 32.2 to 1.5 g kg(-1) (95% degradation) during six months of treatment. PMID:27354013

  16. Subsurface Characterization To Support Evaluation Of Radionuclide Transport And Attenuation

    EPA Science Inventory

    Remediation of ground water contaminated with radionuclides may be achieved using attenuation-based technologies. These technologies may rely on engineered processes (e.g., bioremediation) or natural processes (e.g., monitored natural attenuation) within the subsurface. In gene...

  17. IN-SITU BIOREMEDIATION OF GROUND WATER AND GEOLOGICAL MATERIAL: A REVIEW OF TECHNOLOGIES

    EPA Science Inventory

    In situ bioremediation of subsurface environments involve the use of microorganisms to convert contaminants to less harmful products and sometimes offers significant potential advantages over other remediation technologies. n order for these biodegradative processes to occur, icr...

  18. Effects of nutrient dosing on subsurface methanotrophic populations and trichloroethylene degradation.

    PubMed

    Pfiffner, S M; Palumbo, A V; Phelps, T J; Hazen, T C

    1997-01-01

    In in situ bioremediation demonstration at the Savannah River Site in Aiken, South Carolina, trichloroethyle degrading microorganisms were stimulated by delivering nutrients to the TCE-contaminated subsurface via horizontal injection wells. Microbial and chemical monitoring of groundwater from 12 vertical wells was used to examine the effects of methane and nutrient (nitrogen and phosphorus) dosing on the methanotrophic populations and on the potential of the subsurface microbial communities to degrade TCE. Densities of methanotrophs increased 3-5 orders of magnitude during the methane- and nutrient-injection phases; this increase coinclded with the higher methane levels observed in the monitoring wells. TCE degradation capacity, although not directly tied to methane concentration, responded to the methane injection, and responded more dramatically to the multiple-nutrient injection. tion. These results support the crucial role of methane, nitrogen, and phosphorus as amended nutrients in TCE bioremediation. The enhancing effects of nutrient dosing on microbial abundance and degradative potentials, coupled with increased chloride concentrations, provided multiple lines of evidence substantiating the effectiveness of this integrated in situ bioremediation process. PMID:9134767

  19. In situ groundwater bioremediation

    SciTech Connect

    Hazen, Terry C.

    2009-02-01

    In situ groundwater bioremediation of hydrocarbons has been used for more than 40 years. Most strategies involve biostimulation; however, recently bioaugmentation have been used for dehalorespiration. Aquifer and contaminant profiles are critical to determining the feasibility and strategy for in situ groundwater bioremediation. Hydraulic conductivity and redox conditions, including concentrations of terminal electron acceptors are critical to determine the feasibility and strategy for potential bioremediation applications. Conceptual models followed by characterization and subsequent numerical models are critical for efficient and cost effective bioremediation. Critical research needs in this area include better modeling and integration of remediation strategies with natural attenuation.

  20. Subtask 1.16-Slow-Release Bioremediation Accelerators

    SciTech Connect

    Marc D. Kurz; Edwin S. Olson

    2006-07-31

    Low-cost methods are needed to enhance various bioremediation technologies, from natural attenuation to heavily engineered remediation of subsurface hydrocarbon contamination. Many subsurface sites have insufficient quantities of nitrogen and phosphorus, resulting in poor bioactivity and increased remediation time and costs. The addition of conventional fertilizers can improve bioactivity, but often the nutrients dissolve quickly and migrate away from the contaminant zone before being utilized by the microbes. Through this project, conducted by the Energy & Environmental Research Center, polymers were developed that slowly release nitrogen and phosphorus into the subsurface. Conceptually, these polymers are designed to adhere to soil particles in the subsurface contamination zone where they slowly degrade and release nutrients over longer periods of time compared to conventional fertilizer applications. Tests conducted during this study indicate that some of the developed polymers have excellent potential to satisfy the microbial requirements for enhanced bioremediation.

  1. Molecular analysis of phosphate limitation in Geobacteraceae during the bioremediation of a uranium-contaminated aquifer

    SciTech Connect

    N'Guessan, L.A.; Elifantz, H.; Nevin, K.P.; Mouser, P.J.; Methe, B.; Woodard, T. L.; Manley, K.; Williams, K. H.; Wilkins, M. J.; Larsen, J.T.; Long, P. E.; Lovley, D. R.

    2009-09-01

    Nutrient limitation is an environmental stress that may reduce the effectiveness of bioremediation strategies, especially when the contaminants are organic compounds or when organic compounds are added to promote microbial activities such as metal reduction. Genes indicative of phosphate-limitation were identified via microarray analysis of chemostat cultures of Geobacter sulfureducens. This analysis revealed that genes in the pst-pho operon, which is associated with a high affinity phosphate uptake system in other microorganisms, had significantly higher transcript abundance under phosphate-limiting conditions, with the genes pstB and phoU the most up-regulated. Quantitative PCR analysis of pstB and phoU transcript levels in G. sulfurreducens grown in chemostats demonstrated that the expression of these genes increased when phosphate was removed from the culture medium. Transcripts of pstB and phoU within the subsurface Geobacter species predominating during an in situ uranium bioremediation field experiment were more abundant than in chemostat cultures of G. sulfurreducens that were not limited for phosphate. Addition of phosphate to incubations of subsurface sediments did not stimulate dissimilatory metal reduction. The added phosphate was rapidly adsorbed onto the sediments. The results demonstrate that Geobacter species can effectively reduce U(VI) even when experiencing suboptimal phosphate concentrations and that increasing phosphate availability with phosphate additions is difficult to achieve due to the high reactivity of this compound. This transcript-based approach developed for diagnosing phosphate limitation should be applicable to assessing the potential need for additional phosphate in other bioremediation processes.

  2. Molecular Analysis of Phosphate Limitation in Geobacteraceae During the Bioremediation of a Uranium-Contaminated Aquifer

    SciTech Connect

    N'Guessan, A. Lucie; Elifantz, H.; Nevin, Kelly P.; Mouser, Paula; Methe, Barbara; Woodard, Trevor L.; Manley, Kimberley; Williams, Kenneth H.; Wilkins, Michael J.; Larsen, Joern T.; Long, Philip E.; Lovley, Derek R.

    2010-02-01

    Nutrient limitation is an environmental stress that may reduce the effectiveness of bioremediation strategies, especially when the contaminants are organic compounds or when organic compounds are added to promote microbial activities such as metal reduction. Genes indicative of phosphate-limitation were identified via microarray analysis of chemostat cultures of Geobacter sulfureducens. This analysis revealed that genes in the pst-pho operon, which is associated with a high affinity phosphate uptake system in other microorganisms, had significantly higher transcript abundance under phosphate-limiting conditions, with the genes pstB and phoU the most up-regulated. Quantitative PCR analysis of pstB and phoU transcript levels in G. sulfurreducens grown in chemostats demonstrated that the expression of these genes increased when phosphate was removed from the culture medium. Transcripts of pstB and phoU within the subsurface Geobacter species predominating during an in situ uranium bioremediation field experiment were more abundant than in chemostat cultures of G. sulfurreducens that were not limited for phosphate. Addition of phosphate to incubations of subsurface sediments did not stimulate dissimilatory metal reduction. The added phosphate was rapidly adsorbed onto the sediments. The results demonstrate that Geobacter species can effectively reduce U(VI) even when experiencing suboptimal phosphate concentrations and that increasing phosphate availability with phosphate additions is difficult to achieve due to the high reactivity of this compound. This transcript-based approach developed for diagnosing phosphate limitation should be applicable to assessing the potential need for additional phosphate in other bioremediation processes.

  3. Molecular analysis of phosphate limitation in Geobacteraceae during the bioremediation of a uranium-contaminated aquifer

    SciTech Connect

    N'Guessan, A. Lucie; Elifantz, H.; Nevin, Kelly P.; Mouser, Paula; Methe, Barbara; Woodard, Trevor L.; Manley, Kimberley; Williams, Kenneth H.; Wilkins, Michael J.; Larsen, Joern T.; Long, Philip E.; Lovley, Derek R.

    2010-01-10

    Nutrient limitation is an environmental stress that may reduce the effectiveness of bioremediation strategies, especially when the contaminants are organic compounds or when organic compounds are added to promote microbial activities such as metal reduction. Genes indicative of phosphatelimitation were identified by microarray analysis of chemostat cultures of Geobacter sulfureducens. This analysis revealed that genes in the pst-pho operon, which is associated with a high-affinity phosphate uptake system in other microorganisms, had significantly higher transcript abundance under phosphate-limiting conditions, with the genes pstB and phoU upregulated the most. Quantitative PCR analysis of pstB and phoU transcript levels in G. sulfurreducens grown in chemostats demonstrated that the expression of these genes increased when phosphate was removed from the culture medium. Transcripts of pstB and phoU within the subsurface Geobacter species predominating during an in situ uranium-bioremediation field experiment were more abundant than in chemostat cultures of G. sulfurreducens that were not limited for phosphate. Addition of phosphate to incubations of subsurface sediments did not stimulate dissimilatory metal reduction. The added phosphate was rapidly adsorbed onto the sediments. The results demonstrate that Geobacter species can effectively reduce U(VI) even when experiencing suboptimal phosphate concentrations and that increasing phosphate availability with phosphate additions is difficult to achieve because of the high reactivity of this compound. This transcript-based approach developed for diagnosing phosphate limitation should be applicable to assessing the potential need for additional phosphate in other bioremediation processes.

  4. Geoelectrical Signatures Of Microbial Stimulated Mineralization

    NASA Astrophysics Data System (ADS)

    Personna, Y. R.; Ntarlagiannis, D.; Slater, L.; O Brien, M.; Hubbard, S.; Williams, K. H.

    2007-05-01

    Bioremediation techniques are commonly utilized to address soil and groundwater contamination due to acid- mine drainage, industrial sources, and government nuclear weapon programs. One critical component of these efforts is the real time, spatially accurate monitoring of the remediation processes. For this reason non-invasive high resolution geophysical methods have been employed in the recent years to elucidate system transformations occurring during bioremediation. In our study, we performed laboratory column experiments to investigate the geoelectrical response of microbe-mediated iron sulfide (FeS) precipitation accompanying stimulated sulfate-reduction; a bioremediation technique currently utilized for the sequestration of heavy metals in the subsurface. In order to monitor the biomineralization process, we used two geoelectrical methods - induced polarization (IP) and self-potential (SP) - in conjunction with conventional geochemical measurements. The IP data showed significant anomalies associated with ongoing FeS mineralization accompanying microbial activity. The magnitude of the IP response can be considered a proxy for the mass of minerals accumulating in the pore space and may provide insight into the aggregation state of the mineralization. Additionally, strong SP anomalies developed during the mineralization as a result of the continuous redox state changes following the microbial induced mineral formation. Visibly black precipitates accumulated with the column indicating FeS precipitation, and high H2S content confirmed the observed geochemical and geophysical data. Overall, the results suggest that the IP and SP methods can be used to monitor the progress of the microbial induced mineralization process associated with the precipitation of insoluble metal sulfides, and indirectly monitor the microbial activity within the subsurface. These methods can be valuable tools to increase the efficiency of bioremediation techniques.

  5. Enhanced In Situ Bioremediation. Innovative Technology Summary Report

    SciTech Connect

    2002-03-01

    Enhanced In-Situ Bioremediation (ISB) provides increased degradation of contaminants in the subsurface by indigenous microorganisms present in the soil by manipulating this natural process. In addition, there is reduced worker risk, and decreased waste management costs associated with traditional pump and treat technology.

  6. ENGINEERING CONCEPTS FOR IN SITU BIOREMEDIATION. (R825689C051)

    EPA Science Inventory

    Abstract

    Most organic materials that contaminate soil and the subsurface environment are readily degraded by natural biological processes. Thus, bioremediation can be thought of as a highly successful purification process. However, some organic molecules are naturally ...

  7. Accelerated in situ bioremediation of groundwater

    SciTech Connect

    Truex, M.J.; Hooker, B.S.; Anderson, D.B.

    1996-07-01

    In situ bioremediation, as applied in this project, is based on the principal of biostimulation: supplying nutrients to indigenous microbes to stimulate their metabolic activity and subsequent degradation of contaminants. Typically, a network of injection and extraction wells are used to recirculate groundwater into which amendments are added and distributed within the aquifer. The objective of the in situ process is to create in the aquifer a microbially active zone that maximizes contaminant destruction while controlling the distribution of microbial growth. It is important to control microbial growth to avoid plugging the aquifer near the injection well and to establish and sustain maximum treatment zones for each injection well. Figure I illustrates this concept for in situ bioremediation. The technology described herein is innovative in its use of the computer-based Accelerated Bioremediation Design Tool (ABDT) to aid in selecting appropriate system designs and to determine optimal operating strategies. In addition, numerical simulations within the design tool proved to be valuable during remediation operations to determine appropriate changes in the` operating strategy as the bioremediation process progressed. This is particularly important because in situ bioremediation is not a steady- state process, and corrective actions to operating parameters are typically needed to maintain both rapid destruction rates and hydraulic containment.

  8. Genetic Analysis of Stress Responses in Soil Bacteria for Enhanced Bioremediation of Mixed Contaminants

    SciTech Connect

    Wong, Kwong-Kwok

    2000-06-01

    The purpose of this project is to provide fundamental knowledge on environment stress response of subsurface bacteria and a radiation-resistant bacterium (Deinococcus radiodurans). This information will be particularly useful in the development of successful bioremediation strategies. These organisms represent two phylogenetically distinct groups of soil bacteria, each of which has specific features of interest for bioremediation. The subsurface bacteria, Sphingomonas spp (Savannah River Site), have unique degradative capabilities of organic waste. The study of subsurface bacteria will serve as a model for bioremediation using indigenous bacteria. D. radiodurans exhibits high resistance to external stress such as ionizing radiation and organic solvent. The study of D. radiodurans will serve as a model for the use of genetically engineered bacteria for bioremediation.

  9. Development of a biomarker for Geobacter activity and strain composition: Proteogenomic analysis of the citrate synthase protein during bioremediation of U(VI)

    SciTech Connect

    Wilkins, M.J.; Callister, S.J.; Miletto, M.; Williams, K.H.; Nicora, C.D.; Lovley, D.R.; Long, P.E.; Lipton, M.S.

    2010-02-15

    Monitoring the activity of target microorganisms during stimulated bioremediation is a key problem for the development of effective remediation strategies. At the US Department of Energy's Integrated Field Research Challenge (IFRC) site in Rifle, CO, the stimulation of Geobacter growth and activity via subsurface acetate addition leads to precipitation of U(VI) from groundwater as U(IV). Citrate synthase (gltA) is a key enzyme in Geobacter central metabolism that controls flux into the TCA cycle. Here, we utilize shotgun proteomic methods to demonstrate that the measurement of gltA peptides can be used to track Geobacter activity and strain evolution during in situ biostimulation. Abundances of conserved gltA peptides tracked Fe(III) reduction and changes in U(VI) concentrations during biostimulation, whereas changing patterns of unique peptide abundances between samples suggested sample-specific strain shifts within the Geobacter population. Abundances of unique peptides indicated potential differences at the strain level between Fe(III)-reducing populations stimulated during in situ biostimulation experiments conducted a year apart at the Rifle IFRC. These results offer a novel technique for the rapid screening of large numbers of proteomic samples for Geobacter species and will aid monitoring of subsurface bioremediation efforts that rely on metal reduction for desired outcomes.

  10. Development of a biomarker for Geobacter activity and strain composition; Proteogenomic analysis of the citrate synthase protein during bioremediation of U(VI).

    SciTech Connect

    Wilkins, Michael J.; Callister, Stephen J.; Miletto, Marzia; Williams, Kenneth H.; Nicora, Carrie D.; Lovely, Derek R.; Long, Philip E.; Lipton, Mary S.

    2011-01-01

    Monitoring the activity of target microorganisms during stimulated bioremediation is a key problem for the development of effective remediation strategies. At the U.S. Department of Energy’s Integrated Field Research Challenge (IFRC) site in Rifle, CO, the stimulation of Geobacter growth and activity via subsurface acetate addition leads to precipitation of U(VI) from groundwater as U(IV). Citrate synthase (gltA) is a key enzyme in Geobacter central metabolism that controls flux into the TCA cycle. Here, we utilize shotgun proteomic methods to demonstrate that the measurement of gltA peptides can be used to track Geobacter activity and strain evolution during in situ biostimulation. Abundances of conserved gltA peptides tracked Fe(III) reduction and changes in U(VI) concentrations during biostimulation, whereas changing patterns of unique peptide abundances between samples suggested sample-specific strain shifts within the Geobacter population. Abundances of unique peptides indicated potential differences at the strain level between Fe(III)-reducing populations stimulated during in situ biostimulation experiments conducted a year apart at the Rifle IFRC. These results offer a novel technique for the rapid screening of large numbers of proteomic samples for Geobacter species and will aid monitoring of subsurface bioremediation efforts that rely on metal reduction for desired outcomes.

  11. Simulation of oil bioremediation in a tidally influenced beach: Spatiotemporal evolution of nutrient and dissolved oxygen

    NASA Astrophysics Data System (ADS)

    Geng, Xiaolong; Pan, Zhong; Boufadel, Michel C.; Ozgokmen, Tamay; Lee, Kenneth; Zhao, Lin

    2016-04-01

    Numerical experiments of oil bioremediation of tidally influenced beach were simulated using the model BIOMARUN. Nutrient and dissolved oxygen were assumed present in a solution applied on the exposed beach face, and the concentration of these amendments was tracked throughout the beach for up to 6 months. It was found that, in comparison to natural attenuation, bioremediation increased the removal efficiency by 76% and 65% for alkanes and aromatics, respectively. Increasing the nutrient concentration in the applied solution did not always enhance biodegradation as oxygen became limiting even when the beach was originally oxygen-rich. Therefore, replenishment of oxygen to oil-contaminated zone was also essential. Stimulation of oil biodegradation was more evident in the upper and midintertidal zone of the beach, and less in the lower intertidal zone. This was due to reduced nutrient and oxygen replenishment, as very little of the amendment solution reached that zone. It was found that under continual application, most of the oil biodegraded within 2 months, while it persisted for 6 months under natural conditions. While the difference in duration suggests minimal long-term effects, there are situations where the beach would need to be cleaned for major ecological functions, such as temporary nesting or feeding for migratory birds. Biochemical retention time map (BRTM) showed that the duration of solution application was dependent upon the stimulated oil biodegradation rate. By contrast, the application rate of the amendment solution was dependent upon the subsurface extent of the oil-contaminated zone. Delivery of nutrient and oxygen into coastal beach involved complex interaction among amendment solution, groundwater, and seawater. Therefore, approaches that ignore the hydrodynamics due to tide are unlikely to provide the optimal solutions for shoreline bioremediation.

  12. Fungi in Bioremediation

    NASA Astrophysics Data System (ADS)

    Gadd, G. M.

    2001-12-01

    Bioremediation research has concentrated on organic pollutants, although the range of substances that can be transformed or detoxified by microorganisms includes both natural and synthetic organic materials and inorganic pollutants. The majority of applications developed to date involve bacteria, with a distinct lack of appreciation of the potential roles and involvement of fungi in bioremediation, despite clear evidence of their metabolic and morphological versatility. This book highlights the potential of filamentous fungi, including mycorrhizas, in bioremediation and discusses the physiology and chemistry of pollutant transformations.

  13. DEMONSTRATION BULLETIN: SUBSURFACE VOLATILIZATION AND VENTILATION SYSTEM - BROWN & ROOT ENVIRONMENTAL

    EPA Science Inventory

    The Subsurface Volatilization and Ventilation System (SVVS*) is an in-situ vacuum extraction/air sparging and bioremediation technology for the treatment of subsurface organic contamination in soil and groundwater. The technology, developed by Billings and Associates, Inc., and o...

  14. DEMONSTRATION BULLETIN: NEW YORK STATE MULTI-VENDOR BIOREMEDIATION - R.E. WRIGHT ENVIRONMENTAL, INC.'S IN-SITU BIOREMEDIATION TREATMENT SYSTEM

    EPA Science Inventory

    The R.E. Wright Environmental, Inc.‘s (REWEI) In-situ Bioremediation Treatment System is an in-situ bioremediation technology for the treatment of soils contaminated with organic compounds. According to the Developer, contaminated soils are remediated in-situ by stimulating the a...

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

    SciTech Connect

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

    2007-12-01

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

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

    SciTech Connect

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

    1992-12-31

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

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

    SciTech Connect

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

    1992-01-01

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

  18. Silica-Based Carbon Source Delivery for In-situ Bioremediation Enhancement

    NASA Astrophysics Data System (ADS)

    Zhong, L.; Lee, M. H.; Lee, B.; Yang, S.

    2015-12-01

    Colloidal silica aqueous suspensions undergo viscosity increasing and gelation over time under favorable geochemical conditions. This property of silica suspension can potentially be applied to deliver remedial amendments to the subsurface and establish slow release amendment sources for enhanced remediation. In this study, silica-based delivery of carbon sources for in-situ bioremediation enhancement is investigated. Sodium lactate, vegetable oil, ethanol, and molasses have been studied for the interaction with colloidal silica in aqueous suspensions. The rheological properties of the carbon source amendments and silica suspension have been investigated. The lactate-, ethanol-, and molasses-silica suspensions exhibited controllable viscosity increase and eventually became gels under favorable geochemical conditions. The gelation rate was a function of the concentration of silica, salinity, amendment, and temperature. The vegetable oil-silica suspensions increased viscosity immediately upon mixing, but did not perform gelation. The carbon source release rate from the lactate-, ethanol-, and molasses-silica gels was determined as a function of silica, salinity, amendment concentration. The microbial activity stimulation and in-situ bioremediation enhancement by the slow-released carbon from the amendment-silica gels will be demonstrated in future investigations planned in this study.

  19. Numerical simulations for the in situ bioremediation demonstration at Savannah River: Presentation of the model

    SciTech Connect

    Travis, B.J.; Rosenberg, N.D.; Birdsell, K.H.

    1992-01-01

    A series of environmental technology field tests, including in situ bioremediation, are being conducted at the Savannah River Integrated Demonstration (SRID) site near Aiken, South Carolina. This site is part of a larger area that was used to process fuel and target elements for use in reactors. Degreasing operations were included at several stages of the operations. Degreasers such as TCE and PCE were discharged to a seepage basin via a process sewer pipeline. In the early 1980s, inspections revealed that the process sewer line had extensive cracks, allowing solvents to leak into the subsurface environment. An in situ remediation technology designed to address this linear source term was tested in 1990. This technology involved air injection below the water table and vacuum extraction in the vadose zone using two horizontal wells [Looney et al., 1991]. Bioremediation experiments using these same horizontal wells were begun in 1992 [Hazen, 1992a]. This reports describes the experiment, which is based on the expectation that the injected air and methane will stimulate the growth of naturally occurring methanotrophs at the site and these bacteria will co-metabolize the chlorinated solvents.

  20. Diagnosis of In Situ Metabolic State and Rates of Microbial Metabolism During In Situ Uranium Bioremediation with Molecular Techniques

    SciTech Connect

    Lovley, Derek R

    2012-11-28

    The goal of these projects was to develop molecule tools to tract the metabolic activity and physiological status of microorganisms during in situ uranium bioremediation. Such information is important in able to design improved bioremediation strategies. As summarized below, the research was highly successful with new strategies developed for estimating in situ rates of metabolism and diagnosing the physiological status of the predominant subsurface microorganisms. This is a first not only for groundwater bioremediation studies, but also for subsurface microbiology in general. The tools and approaches developed in these studies should be applicable to the study of microbial communities in a diversity of soils and sediments.

  1. Field evaluations of marine oil spill bioremediation.

    PubMed Central

    Swannell, R P; Lee, K; McDonagh, M

    1996-01-01

    Bioremediation is defined as the act of adding or improving the availability of materials (e.g., nutrients, microorganisms, or oxygen) to contaminated environments to cause an acceleration of natural biodegradative processes. The results of field experiments and trials following actual spill incidents have been reviewed to evaluate the feasibility of this approach as a treatment for oil contamination in the marine environment. The ubiquity of oil-degrading microorganisms in the marine environment is well established, and research has demonstrated the capability of the indigenous microflora to degrade many components of petroleum shortly after exposure. Studies have identified numerous factors which affect the natural biodegradation rates of oil, such as the origin and concentration of oil, the availability of oil-degrading microorganisms, nutrient concentrations, oxygen levels, climatic conditions, and sediment characteristics. Bioremediation strategies based on the application of fertilizers have been shown to stimulate the biodegradation rates of oil in aerobic intertidal sediments such as sand and cobble. The ratio of oil loading to nitrogen concentration within the interstitial water has been identified to be the principal controlling factor influencing the success of this bioremediation strategy. However, the need for the seeding of natural environments with hydrocarbon-degrading bacteria has not been clearly demonstrated under natural environmental conditions. It is suggested that bioremediation should now take its place among the many techniques available for the treatment of oil spills, although there is still a clear need to set operational limits for its use. On the basis of the available evidence, we have proposed preliminary operational guidelines for bioremediation on shoreline environments. PMID:8801437

  2. Field evaluations of marine oil spill bioremediation.

    PubMed

    Swannell, R P; Lee, K; McDonagh, M

    1996-06-01

    Bioremediation is defined as the act of adding or improving the availability of materials (e.g., nutrients, microorganisms, or oxygen) to contaminated environments to cause an acceleration of natural biodegradative processes. The results of field experiments and trials following actual spill incidents have been reviewed to evaluate the feasibility of this approach as a treatment for oil contamination in the marine environment. The ubiquity of oil-degrading microorganisms in the marine environment is well established, and research has demonstrated the capability of the indigenous microflora to degrade many components of petroleum shortly after exposure. Studies have identified numerous factors which affect the natural biodegradation rates of oil, such as the origin and concentration of oil, the availability of oil-degrading microorganisms, nutrient concentrations, oxygen levels, climatic conditions, and sediment characteristics. Bioremediation strategies based on the application of fertilizers have been shown to stimulate the biodegradation rates of oil in aerobic intertidal sediments such as sand and cobble. The ratio of oil loading to nitrogen concentration within the interstitial water has been identified to be the principal controlling factor influencing the success of this bioremediation strategy. However, the need for the seeding of natural environments with hydrocarbon-degrading bacteria has not been clearly demonstrated under natural environmental conditions. It is suggested that bioremediation should now take its place among the many techniques available for the treatment of oil spills, although there is still a clear need to set operational limits for its use. On the basis of the available evidence, we have proposed preliminary operational guidelines for bioremediation on shoreline environments. PMID:8801437

  3. Bioremediation of nanomaterials

    DOEpatents

    Chen, Frank Fanqing; Keasling, Jay D; Tang, Yinjie J

    2013-05-14

    The present invention provides a method comprising the use of microorganisms for nanotoxicity study and bioremediation. In some embodiment, the microorganisms are bacterial organisms such as Gram negative bacteria, which are used as model organisms to study the nanotoxicity of the fullerene compounds: E. coli W3110, a human related enterobacterium and Shewanella oneidensis MR-1, an environmentally important bacterium with versatile metabolism.

  4. Monitoring Physical and Biogeochemical Dynamics of Uranium Bioremediation at the Intermediate Scale

    NASA Astrophysics Data System (ADS)

    Tarrell, A. N.; Figueroa, L. A.; Rodriguez, D.; Haas, A.; Revil, A.

    2011-12-01

    Subsurface uranium above desired levels for aquifer use categories exists naturally and from historic mining and milling practices. In situ bioimmobilization offers a cost effective alternative to conventional pump and treat methods by stimulating growth of microorganisms that lead to the reduction and precipitation of uranium. Vital to the long-term success of in situ bioimmobilization is the ability to successfully predict and demonstrate treatment effectiveness to assure that regulatory goals are met. However, successfully monitoring the progress over time is difficult and requires long-term stewardship to ensure effective treatment due to complex physical and biogeochemical heterogeneity. In order to better understand these complexities and the resultant effect on uranium immobilization, innovative systematic monitoring approaches with multiple performance indicators must be investigated. A key issue for uranium bioremediation is the long term stability of solid-phase reduction products. It has been shown that a combination of data from electrode-based monitoring, self-potential monitoring, oxidation reduction potential (ORP), and water level sensors provides insight for identifying and localizing bioremediation activity and can provide better predictions of deleterious biogeochemical change such as pore clogging. In order to test the proof-of-concept of these sensing techniques and to deconvolve redox activity from other electric potential changing events, an intermediate scale 3D tank experiment has been developed. Well-characterized materials will be packed into the tank and an artificial groundwater will flow across the tank through a constant-head boundary. The experiment will utilize these sensing methods to image the electrical current produced by bacteria as well as indications of when and where electrical activity is occurring, such as with the reduction of radionuclides. This work will expand upon current knowledge by exploring the behavior of uranium

  5. Using Geophysical Signatures to Investigate Temporal Changes Due to Source Reduction in the Subsurface Contaminated with Hydrocarbons

    EPA Science Inventory

    We investigated the geophysical response to subsurface hydrocarbon contamination source removal. Source removal by natural attenuation or by engineered bioremediation is expected to change the biological, chemical, and physical environment associated with the contaminated matrix....

  6. In Situ Expression of nifD in Geobacteraceae in Subsurface Sediments

    PubMed Central

    Holmes, Dawn E.; Nevin, Kelly P.; Lovley, Derek R.

    2004-01-01

    In order to determine whether the metabolic state of Geobacteraceae involved in bioremediation of subsurface sediments might be inferred from levels of mRNA for key genes, in situ expression of nifD, a highly conserved gene involved in nitrogen fixation, was investigated. When Geobacter sulfurreducens was grown without a source of fixed nitrogen in chemostats with acetate provided as the limiting electron donor and Fe(III) as the electron acceptor, levels of nifD transcripts were 4 to 5 orders of magnitude higher than in chemostat cultures provided with ammonium. In contrast, the number of transcripts of recA and the 16S rRNA gene were slightly lower in the absence of ammonium. The addition of acetate to organic- and nitrogen-poor subsurface sediments stimulated the growth of Geobacteraceae and Fe(III) reduction, as well as the expression of nifD in Geobacteraceae. Levels of nifD transcripts in Geobacteraceae decreased more than 100-fold within 2 days after the addition of 100 μM ammonium, while levels of recA and total bacterial 16S rRNA in Geobacteraceae remained relatively constant. Ammonium amendments had no effect on rates of Fe(III) reduction in acetate-amended sediments or toluene degradation in petroleum-contaminated sediments, suggesting that other factors, such as the rate that Geobacteraceae could access Fe(III) oxides, limited Fe(III) reduction. These results demonstrate that it is possible to monitor one aspect of the in situ metabolic state of Geobacteraceae species in subsurface sediments via analysis of mRNA levels, which is the first step toward a more global analysis of in situ gene expression related to nutrient status and stress response during bioremediation by Geobacteraceae. PMID:15574924

  7. GENETIC ANALYSIS OF STRESS RESPONSES IN SOIL BACTERIA FOR ENHANCED BIOREMEDIATION OF MIXED CONTAMINANTS

    EPA Science Inventory

    Bioremediation is, in some cases, a cost-effective approach to site clean-up. However, to realize the full potential of this biological process, fundamental information is needed about genetic responses of bacteria to environmental factors in the contaminated subsurface. Identifi...

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

    SciTech Connect

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

    2004-11-14

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

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

    NASA Astrophysics Data System (ADS)

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

    2005-05-01

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

  10. Principles of Bioremediation Assessment

    NASA Astrophysics Data System (ADS)

    Madsen, E. L.

    2001-12-01

    Although microorganisms have successfully and spontaneously maintained the biosphere since its inception, industrialized societies now produce undesirable chemical compounds at rates that outpace naturally occurring microbial detoxification processes. This presentation provides an overview of both the complexities of contaminated sites and methodological limitations in environmental microbiology that impede the documentation of biodegradation processes in the field. An essential step toward attaining reliable bioremediation technologies is the development of criteria which prove that microorganisms in contaminated field sites are truly active in metabolizing contaminants of interest. These criteria, which rely upon genetic, biochemical, physiological, and ecological principles and apply to both in situ and ex situ bioremediation strategies include: (i) internal conservative tracers; (ii) added conservative tracers; (iii) added radioactive tracers; (iv) added isotopic tracers; (v) stable isotopic fractionation patterns; (vi) detection of intermediary metabolites; (vii) replicated field plots; (viii) microbial metabolic adaptation; (ix) molecular biological indicators; (x) gradients of coreactants and/or products; (xi) in situ rates of respiration; (xii) mass balances of contaminants, coreactants, and products; and (xiii) computer modeling that incorporates transport and reactive stoichiometries of electron donors and acceptors. The ideal goal is achieving a quantitative understanding of the geochemistry, hydrogeology, and physiology of complex real-world systems.

  11. Donor-dependent Extent of Uranium Reduction for Bioremediation of Contaminated Sediment Microcosms

    SciTech Connect

    Palumbo, Anthony Vito; Ravel, Bruce; Phelps, Tommy Joe; Schadt, Christopher Warren; Brandt, Craig C

    2009-01-01

    Bioremediation of uranium was investigated in microcosm experiments containing contaminated sediments from Oak Ridge, Tennessee to explore the importance of electron donor selection for uranium reduction rate and extent. In these experiments, all of the electron donors, including ethanol, glucose, methanol, and methanol with added humic acids, stimulated the reduction and immobilization of aqueous uranium by the indigenous microbial community. Uranium loss from solution began after the completion of nitrate reduction but essentially concurrent with sulfate reduction. When electron donor concentrations were normalized for their equivalent electron donor potential yield, the rates of uranium reduction were nearly equivalent for all treatments (0.55-0.95 {micro}mol L{sup -1} d{sup -1}). Uranium reduction with methanol proceeded after a 15-d longer lag time relative to that of ethanol or glucose. Significant differences were not found with the inclusion of humic acids. The extent of U reduction in sediment slurries measured by XANES at various time periods after the start of the experiment increased in the order of ethanol (5-7% reduced at 77 and 153 d), glucose (49% reduced at 53 d), and methanol (93% reduced at 90 d). The microbial diversity of ethanol- and methanol-amended microcosms in their late stage of U reduction was analyzed with 16S rRNA gene amplification. Members of the Geobacteraceae were found in all microcosms as well as other potential uranium-reducing organisms, such as Clostridium and Desulfosporosinus. The effectiveness of methanol relative to ethanol at reducing aqueous and sediment-hosted uranium suggests that bioremediation strategies that encourage fermentative poising of the subsurface to a lower redox potential may be more effective for long-term uranium immobilization as compared with selecting an electron donor that is efficiently metabolized by known uranium-reducing microorganisms.

  12. Donor-dependent Extent of Uranium Reduction for Bioremediation of Contaminated Sediment Microcosms

    SciTech Connect

    Madden, Andrew S.; Palumbo, Anthony V.; Ravel, Bruce; Vishnivetskaya, Tatiana A.; Phelps, Tommy J.; Schadt, Christopher W.; Brandt, Craig C.

    2009-03-16

    Bioremediation of uranium was investigated in microcosm experiments containing contaminated sediments from Oak Ridge, Tennessee to explore the importance of electron donor selection for uranium reduction rate and extent. In these experiments, all of the electron donors, including ethanol, glucose, methanol, and methanol with added humic acids, stimulated the reduction and immobilization of aqueous uranium by the indigenous microbial community. Uranium loss from solution began after the completion of nitrate reduction but essentially concurrent with sulfate reduction. When electron donor concentrations were normalized for their equivalent electron donor potential yield, the rates of uranium reduction were nearly equivalent for all treatments (0.55-0.95 {micro}mol L{sup -1} d{sup -1}). Uranium reduction with methanol proceeded after a 15-d longer lag time relative to that of ethanol or glucose. Significant differences were not found with the inclusion of humic acids. The extent of U reduction in sediment slurries measured by XANES at various time periods after the start of the experiment increased in the order of ethanol (5-7% reduced at 77 and 153 d), glucose (49% reduced at 53 d), and methanol (93% reduced at 90 d). The microbial diversity of ethanol- and methanol-amended microcosms in their late stage of U reduction was analyzed with 16S rRNA gene amplification. Members of the Geobacteraceae were found in all microcosms as well as other potential uranium-reducing organisms, such as Clostridium and Desulfosporosinus. The effectiveness of methanol relative to ethanol at reducing aqueous and sediment-hosted uranium suggests that bioremediation strategies that encourage fermentative poising of the subsurface to a lower redox potential may be more effective for long-term uranium immobilization as compared with selecting an electron donor that is efficiently metabolized by known uranium-reducing microorganisms.

  13. Complete Genome Sequence of Anaeromyxobacter sp. Fw109-5, an Anaerobic, Metal-Reducing Bacterium Isolated from a Contaminated Subsurface Environment.

    PubMed

    Hwang, C; Copeland, A; Lucas, S; Lapidus, A; Barry, K; Glavina Del Rio, T; Dalin, E; Tice, H; Pitluck, S; Sims, D; Brettin, T; Bruce, D C; Detter, J C; Han, C S; Schmutz, J; Larimer, F W; Land, M L; Hauser, L J; Kyrpides, N; Lykidis, A; Richardson, P; Belieav, A; Sanford, R A; Löeffler, F E; Fields, M W

    2015-01-01

    We report the genome sequence of Anaeromyxobacter sp. Fw109-5, isolated from nitrate- and uranium-contaminated subsurface sediment of the Oak Ridge Integrated Field-Scale Subsurface Research Challenge (IFC) site, Oak Ridge Reservation, TN. The bacterium's genome sequence will elucidate its physiological potential in subsurface sediments undergoing in situ uranium bioremediation and natural attenuation. PMID:25614562

  14. Complete genome sequence of Anaeromyxobacter sp. Fw109-5, an Anaerobic, Metal-Reducing Bacterium Isolated from a Contaminated Subsurface Environment

    DOE PAGESBeta

    Hwang, C.; Copeland, A.; Lucas, Susan; Lapidus, Alla; Barry, Kerrie W.; Glavina del Rio, T.; Dalin, Eileen; Tice, Hope; Pitluck, S.; Sims, David R.; et al

    2015-01-22

    We report the genome sequence of Anaeromyxobacter sp. Fw109-5, isolated from nitrate- and uranium-contaminated subsurface sediment of the Oak Ridge Integrated Field-Scale Subsurface Research Challenge (IFC) site, Oak Ridge Reservation, TN. The bacterium’s genome sequence will elucidate its physiological potential in subsurface sediments undergoing in situ uranium bioremediation and natural attenuation.

  15. Mathematical Modelling of Bacterial Populations in Bio-remediation Processes

    NASA Astrophysics Data System (ADS)

    Vasiliadou, Ioanna A.; Vayenas, Dimitris V.; Chrysikopoulos, Constantinos V.

    2011-09-01

    An understanding of bacterial behaviour concerns many field applications, such as the enhancement of water, wastewater and subsurface bio-remediation, the prevention of environmental pollution and the protection of human health. Numerous microorganisms have been identified to be able to degrade chemical pollutants, thus, a variety of bacteria are known that can be used in bio-remediation processes. In this study the development of mathematical models capable of describing bacterial behaviour considered in bio-augmentation plans, such as bacterial growth, consumption of nutrients, removal of pollutants, bacterial transport and attachment in porous media, is presented. The mathematical models may be used as a guide in designing and assessing the conditions under which areas contaminated with pollutants can be better remediated.

  16. GRACE BIOREMEDIATION TECHNOLOGIES - DARAMEND™ BIOREMEDIATION TECHNOLOGY. INNOVATIVE TECHNOLOGY EVALUATION REPORT

    EPA Science Inventory

    Grace Dearborn's DARAMEND™ Bioremediation Technology was developed to treat soils/sediment contaminated with organic contaminants using solid-phase organic amendments. The amendments increase the soil’s ability to supply biologically available water/nutrients to micro...

  17. Influence of heterogeneous ammonium availability on bacterial community structure and the expression of nitrogen fixation and ammonium transporter genes during in situ bioremediation of uranium-contaminated groundwater

    SciTech Connect

    Mouser, P.J.; N'Guessan, A.L.; Elifantz, H.; Holmes, D.E.; Williams, K.H.; Wilkins, M.J.; Long, P.E.; Lovley, D.R.

    2009-04-01

    The impact of ammonium availability on microbial community structure and the physiological status and activity of Geobacter species during in situ bioremediation of uranium-contaminated groundwater was evaluated. Ammonium concentrations varied by as much as two orders of magnitude (<4 to 400 {micro}M) across the study site. Analysis of 16S rRNA gene sequences suggested that ammonium influenced the composition of the microbial community prior to acetate addition with Rhodoferax species predominating over Geobacter species at the site with the highest ammonium, and Dechloromonas species dominating at sites with lowest ammonium. However, once acetate was added, and dissimilatory metal reduction was stimulated, Geobacter species became the predominant organisms at all locations. Rates of U(VI) reduction appeared to be more related to the concentration of acetate that was delivered to each location rather than the amount of ammonium available in the groundwater. In situ mRNA transcript abundance of the nitrogen fixation gene, nifD, and the ammonium importer gene, amtB, in Geobacter species indicated that ammonium was the primary source of nitrogen during in situ uranium reduction, and that the abundance of amtB transcripts was inversely correlated to ammonium levels across all sites examined. These results suggest that nifD and amtB expression by subsurface Geobacter species are closely regulated in response to ammonium availability to ensure an adequate supply of nitrogen while conserving cell resources. Thus, quantifying nifD and amtB expression appears to be a useful approach for monitoring the nitrogen-related physiological status of Geobacter species in subsurface environments during bioremediation. This study also emphasizes the need for more detailed analysis of geochemical/physiological interactions at the field scale, in order to adequately model subsurface microbial processes.

  18. Subsurface sounders

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Airborne or spaceborne electromagnetic systems used to detect subsurface features are discussed. Data are given as a function of resistivity of ground material, magnetic permeability of free space, and angular frequency. It was noted that resistivities vary with the water content and temperature.

  19. Subsurface Mapping

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Target areas for sinking base holes, underground pipelines, etc., can be identified with the assistance of NASA Ames developed technology, by Airborne Pipeline Services, Inc. Subsurface features are computer processed; the system can cover 250 miles a day and was first developed by Applied Science, Inc.

  20. Bioremediation of organic solvents in ground water: A case study--Grandview, Missouri

    SciTech Connect

    Humenik, J.A. )

    1993-10-01

    Organic solvents leaking from underground storage tanks or from spillage pose a serious threat to ground-water quality. Chemicals such as styrene, ethylbenzene, toluene, and methyl-methacrylate are commonly associated with the manufacturing of plastics and fiberglass. After pump-and-treat operations were unsuccessful in remediating ground water contaminated with ethylbenzene and styrene resulting from leaking underground chemical storage tanks, bioremediation was implemented to degrade the contaminants to the Missouri Department of Natural Resources target cleanup limits. Due to low permeability clays and anaerobic subsurface conditions, the bioremediation design consisted of a ground-water recovery system, an aboveground bioreactor to treat ground water, and a recharge network to introduce acclimated microbes, nutrients, and oxygen to the subsurface. Commercially prepared microbial strains and nutrients were utilized for the close-loop system, as insufficient indigenous microbes and nutrients were present in subsurface matrix.

  1. Bioremediation of high explosives

    SciTech Connect

    Kitts, C.L.; Alvarez, M.A.; Hanners, J.L.; Ogden, K.L.; Vanderberg-Twary, L.; Unkefer, P.J.

    1995-09-01

    Manufacture and use of high explosives has resulted in contamination of ground water and soils throughout the world. The use of biological methods for remediation of high explosives contamination has received considerable attention in recent years. Biodegradation is most easily studied using organisms in liquid cultures. Thus, the amount of explosive that can be degraded in liquid culture is quite small. However, these experiments are useful for gathering basic information about the biochemical pathways of biodegradation, identifying appropriate organisms and obtaining rates of degradation. The authors` laboratory has investigated all three major areas of explosives bioremediation: explosives in solution, explosives in soil, and the disposal of bulk explosives from demilitarization operations. They investigated the three explosives most commonly used in modern high explosive formulations: 2,4,6-trinitrotoluene (TNT), hexahydro 1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX).

  2. Bioremediation with oleophilic fertilizer

    SciTech Connect

    Basseres, A.; Ladousse, A.

    1993-12-31

    To enhance hydrocarbon breakdown by indigenous microbial communities, a fertilizer formulation that would keep nutrients in contact with oil, was designed ten years ago by ELF AQUITAINE. The fertilizer known as INIPOL EAP 22 is an oil soluble additive but also an easily biodegradable carbon source (oleic acid). Numerous experiments, in both laboratory and field, have shown that the application of this fertilizer increases the number of hydrocarbon degrading organisms and the extent and rate of hydrocarbon biodegradation Laboratory experiments with radiolabelled hydrocarbons have shown that in addition to its physico chemical role, oleic acid acts as a biological starter, increasing the biomass and the rate of biodegradation. A large bioremediation project in ALASKA has shown that it its possible to enhance the biodegradation of oil through the application of such a fertilizer, on coarse sediments. Recently, on sandy sediments, the use of INIPOL EAP 22 shown a clear development in hydrocarbon specific bacteria, and an increase of the rate of biodegradation.

  3. ORD RESEARCH PRIORITIES IN BIOREMEDIATION

    EPA Science Inventory

    ORD is conducting research on bioremediation impacting Superfund sites, RCRA facilities, underground storage tanks and oil spills. Work supporting Superfund is focused on understanding monitored natural recovery in sediments for contaminants including PCBs and PAHs. Under RCRA,...

  4. BIOREMEDIATION OF PETROLEUM HYDROCARBONS: A FLEXIBLE VARIABLE SPEED TECHNOLOGY

    EPA Science Inventory

    The bioremediation of petroleum hydrocarbons has evolved into a number of different processes. These processes include in-situ aquifer bioremediation, bioventing, biosparging, passive bioremediation with oxygen release compounds, and intrinsic bioremediation. Although often viewe...

  5. Electrokinetic-enhanced bioremediation of organic contaminants: a review of processes and environmental applications.

    PubMed

    Gill, R T; Harbottle, M J; Smith, J W N; Thornton, S F

    2014-07-01

    There is current interest in finding sustainable remediation technologies for the removal of contaminants from soil and groundwater. This review focuses on the combination of electrokinetics, the use of an electric potential to move organic and inorganic compounds, or charged particles/organisms in the subsurface independent of hydraulic conductivity; and bioremediation, the destruction of organic contaminants or attenuation of inorganic compounds by the activity of microorganisms in situ or ex situ. The objective of the review is to examine the state of knowledge on electrokinetic bioremediation and critically evaluate factors which affect the up-scaling of laboratory and bench-scale research to field-scale application. It discusses the mechanisms of electrokinetic bioremediation in the subsurface environment at different micro and macroscales, the influence of environmental processes on electrokinetic phenomena and the design options available for application to the field scale. The review also presents results from a modelling exercise to illustrate the effectiveness of electrokinetics on the supply electron acceptors to a plume scale scenario where these are limiting. Current research needs include analysis of electrokinetic bioremediation in more representative environmental settings, such as those in physically heterogeneous systems in order to gain a greater understanding of the controlling mechanisms on both electrokinetics and bioremediation in those scenarios. PMID:24875868

  6. Hydrogen as an Indicator to Assess Biological Activity During Trace-Metal Bioremediation

    SciTech Connect

    Peter R. Jaffe, John Komlos, Derick Brown

    2005-09-27

    Trace-metal and/or radionuclide bioremediation schemes require that specific redox conditions be achieved at given zones of an aquifer. Tools are therefore needed to identify the terminal electron acceptor processes (TEAPs) that are being achieved during bioremediation in an aquifer. Dissolved hydrogen (H2) concentrations have been shown to correlate with specific TEAPs during bioremediation in an aquifer. Theoretical analysis has shown that these steady-state H2 levels are solely dependent upon the physiological parameters of the hydrogen-consuming microorganisms, with H2 concentrations increasing as each successive TEAP yields less energy for bacterial growth. The objective of this research was to determine if H2 can still be used as an indicator of TEAPs during a uranium bioremediation scheme where an organic substrate is injected into the subsurface and organisms may consume H2 and carbon simultaneously. In addition, the effect of iron bioavailability on H2 concentrations during iron reduction was observed. The first phase of research determined the effect of a competing electron donor (acetate) on the kinetics of H2 utilization by Geobacter sulfurreducens in batch cultures under iron reducing conditions. The results indicate that, though the Monod kinetic coefficients describing the rate of H2 utilization under iron-reducing conditions correlate energetically with the coefficients found in previous experiments under methanogenic and sulfate-reducing conditions, conventionally measured growth kinetics do not predict the steady state H2 levels typical for each TEAP. In addition, with acetate and H2 as simultaneous electron donors, there is slight inhibition between the two electron donors for G. sulfurreducens, and this can be modeled through competitive inhibition terms in the classic Monod formulation, resulting in slightly higher H2 concentrations under steady state conditions in the presence of acetate. This dual-donor model indicates that the steady state H

  7. Deep subsurface carbon cycling in the Nankai Trough (Japan)—Evidence of tectonically induced stimulation of a deep microbial biosphere

    NASA Astrophysics Data System (ADS)

    Riedinger, N.; Strasser, M.; Harris, R. N.; Klockgether, G.; Lyons, T. W.; Screaton, E. J.

    2015-09-01

    The abundance of microbial life and the sources of energy necessary for deep subsurface microbial communities remain enigmatic. Here we investigate deep microbial processes and their potential relationships to tectonic events in sediments from the Nankai Trough offshore Japan, drilled and sampled during IODP (Integrated Ocean Drilling Program) Expedition 316. Observed methane isotope profiles indicate that microbially mediated methane production occurs at Sites C0006 and C0007 in sediments below ˜450 meters below seafloor (mbsf) and ˜425 mbsf, respectively. The active carbon cycling in these deep subsurface sediments is likely related to the highly dynamic tectonic regime at Nankai Trough. We propose that transient increases in temperature have restimulated organic matter degradation at these distinct depths and explore several candidate processes for transient heating. Our favored hypothesis is frictional heating associated with earthquakes. In concert with transient heating leading to the reactivation of recalcitrant organic matter, the heterogeneous sedimentary system provides niches for microbial life. The newly available/accessible organic carbon compounds fuel the microbial community—resulting in an onset of methanogenesis several hundred meters below the seafloor. This process is captured in the methane C-isotope signal, showing the efficacy of methane C-isotopes for delineating locations of active microbial processes in deeply buried sediments. Additionally, simple model approaches applied to observed chemical pore water profiles can potentially constrain timing relationships, which can then be linked to causative tectonic events. Our results suggest the occurrence of slip-to-the-trench earthquake(s) 200-400 year ago, which could relate to historical earthquakes (1707 Hoei and/or 1605 Keicho earthquakes).

  8. Microbial Metabolite Production for Accelerated Metal and Radionuclide Bioremediation (Microbial Metabolite Production Report)

    SciTech Connect

    TURICK, CHARLES

    2004-09-21

    Biogeochemical activity is an ongoing and dynamic process due to bacterial activity in the subsurface. Bacteria contribute significantly to biotransformation of metals and radionuclides. As basic science reveals more information about specific mechanisms of bacterial-metal reduction, an even greater contribution of bacteria to biogeochemical activities is realized. An understanding and application of the mechanisms of metal and radionuclide reduction offers tremendous potential for development into bioremedial processes and technologies. Most bacteria are capable of biogeochemical transformation as a result of meeting nutrient requirements. These assimilatory mechanisms for metals transformation include production of small molecules that serve as electron shuttles for metal reduction. This contribution to biogeochemistry is small however due to only trace requirements for minerals by bacteria. Dissimilatory metal reducing bacteria (DMRB) reduce oxidized metals and insoluble mineral oxides as a means for biological energy production during growth. These types of bacteria offer considerable potential for bioremediation of environments contaminated with toxic metals and radionuclides because of the relatively large amount of metal biotransformation they require for growth. One of the mechanisms employed by some DMRB for electron transfer to insoluble metal oxides is melanin production. The electrochemical properties of melanin provide this polymeric, humic-type compound with electron shuttling properties. Melanin, specifically, pyomelanin, increases the rate and degree of metal reduction in DMRB as a function of pyomelanin concentration. Due to its electron shuttling behavior, only low femtogram quantities per cell are required to significantly increase metal reduction capacity of DMRB. Melanin production is not limited to DMRB. In fact melanin is one of the most common pigments produced by biological systems. Numerous soil microorganisms produce melanin, contributing

  9. New technologies for subsurface barrier wall construction

    SciTech Connect

    Mutch, R.D. Jr.; Ash, R.E. IV; Caputi, J.R.

    1996-12-31

    New technologies for subsurface barrier wall construction are entering the marketplace at an unprecedented pace. Much of this innovation centers around construction of geomembrane barrier walls but also includes advancements in self-hardening slurries and in permeation grouts, involving such diverse materials as colloidal silica gel and montan wax emulsions. These advancements come at a time when subsurface barrier walls are cautiously emerging out of the technological closet. During much of the 1980s, barrier walls of any type were regarded in some quarters as crude and antiquated. It was correspondingly predicted that remediation would be dominated by emerging treatment technologies such as bioremediation, air sparging, and surfactant flushing. Notwithstanding the considerable successes of these emerging technologies, particularly bioremediation, the fact remains that a significant percentage of Superfund, RCRA-corrective action and other waste disposal sites present hydrogeologic, chemical, and waste matrix complexities that far exceed the capabilities of current treatment-based remedial technologies. Consequently, containment-based technologies such as subsurface barrier walls and caps are being recognized once again as irreplaceable components of practical remediation programs at many complex sites.

  10. Surfactant-enhanced bioremediation

    SciTech Connect

    Churchill, P.F.; Dudley, R.J.; Churchill, S.A.

    1995-12-31

    This study was undertaken to examine the effect of three structurally related, non-ionic surfactants, Triton X-45, Triton X-100 and Triton X-165, as well as the oleophilic fertilizer, Inipol EAP 22, on the rate of biodegradation of phenanthrene by pure bacterial cultures. Each surfactant dramatically increased the apparent aqueous solubility of phenanthrene. Model studies were conducted to investigate the ability of these surfactants to enhance the rate of transport and uptake of polycyclic aromatic hydrocarbons into bacterial cells, and to assess the impact that increasing the aqueous solubility of hydrocarbons has on their rate of biodegradation. The results indicate that increasing the apparent aqueous solubility of hydrocarbons can lead to enhanced biodegradation rates by two Pseudomonas saccharophila strains. However, the experiments also suggest that some surfactants can inhibit aromatic hydrocarbon biodegradation by certain bacteria. The data also support the hypothesis that surface-active components present in the oleophilic fertilizer formulation, Inipol EAP 22, may have significantly contributed to the positive results reported in tests of remedial agent impact on bioremediation, which was used as a supplemental clean-up technology on Exxon Valdez crude oil-contaminated Alaskan beaches.

  11. ENHANCING STAKEHOLDER ACCEPTANCE OF BIOREMEDIATION TECHNOLOGIES

    SciTech Connect

    Focht, Will; Albright, Matt; Anex, Robert P., Jr., ed.

    2009-04-21

    This project inquired into the judgments and beliefs of people living near DOE reservations and facilities at Oak Ridge, Tennessee; Hanford, Washington; and Los Alamos, Tennessee about bioremediation of subsurface contamination. The purpose of the investigation was to identify strategies based on these judgments and beliefs for enhancing public support of bioremediation. Several methods were used to collect and analyze data including content analysis of transcripts of face-to-face personal interviews, factor analysis of subjective perspectives using Q methodology, and statistical analysis of results from a large-sample randomized telephone survey. Content analysis of interview transcripts identified themes about public perceptions and constructions of contamination risk, risk management, and risk managers. This analysis revealed that those who have no employment relationship at the sites and are not engaged in technical professions are most concerned about contamination risks. We also found that most interviewees are unfamiliar with subsurface contamination risks and how they can be reduced, believe they have little control over exposure, are frustrated with the lack of progress in remediation, are concerned about a lack of commitment of DOE to full remediation, and distrust site managers to act in the public interest. Concern is also expressed over frequent site management turnover, excessive secrecy, ineffective and biased communication, perceived attempts to talk the public into accepting risk, and apparent lack of concern about community welfare. In the telephone survey, we asked respondents who were aware of site contamination about their perceptions of risk from exposure to subsurface contamination. Response analysis revealed that most people believe that they are at significant risk from subsurface contamination but they acknowledge that more education is needed to calibrate risk perceptions against scientific risk assessments. Most rate their personal

  12. Electron flow in acidic subsurface sediments co-contaminated with nitrate and uranium

    NASA Astrophysics Data System (ADS)

    Edwards, Lainie; Küsel, Kirsten; Drake, Harold; Kostka, Joel E.

    2007-02-01

    The combination of low pH and high concentrations of nitrate and radionuclides in the subsurface is representative of many sites within the U.S. nuclear weapons complex managed by the Department of Energy (DOE), including the DOE's Environmental Remediation Sciences Program Field Research Center (ORFRC), in Oak Ridge, Tennessee. In order to provide a further understanding of the coupled microbiological and geochemical processes limiting radionuclide bioremediation, we determined the rates and pathways of terminal-electron accepting processes (TEAPs) in microcosm experiments using close to in situ conditions with ORFRC subsurface materials. At the in situ pH range of 4-5, carbon substrate utilization and TEAP rates were diminished, such that nitrate was not depleted and metal reduction was prevented. Upon biostimulation by pH neutralization and carbon substrate addition, TEAPs were stimulated to rates that rival those measured in organic-rich surficial sediments of aquatic environments, and extremely high nitrate concentrations (0.4-0.5 M) were not found to be toxic to microbial metabolism. Metal reduction under neutral pH conditions started once nitrate was depleted to low levels in response to biostimulation. Acidity controlled not only the rates but also the pathways of microbial activity. Denitrification predominated in sediments originating from neutral pH zones, while dissimilatory nitrate reduction to ammonium occurred in neutralized acidic microcosms amended with glucose. Electron donors were determined to stimulate microbial metabolism leading to metal reduction in the following order: glucose > ethanol > lactate > hydrogen. In microcosms of neutralized acidic sediments, 80-90% of C equivalents were recovered as fermentation products, mainly as acetate. Due to the stress imposed by low pH on microbial metabolism, our results indicate that the TEAPs of acidic subsurface sediment are inherently different from those of neutral pH environments and

  13. Systems biology approach to bioremediation

    SciTech Connect

    Chakraborty, Romy; Wu, Cindy H.; Hazen, Terry C.

    2012-06-01

    Bioremediation has historically been approached as a ‘black box’ in terms of our fundamental understanding. Thus it succeeds and fails, seldom without a complete understanding of why. Systems biology is an integrated research approach to study complex biological systems, by investigating interactions and networks at the molecular, cellular, community, and ecosystem level. The knowledge of these interactions within individual components is fundamental to understanding the dynamics of the ecosystem under investigation. Finally, understanding and modeling functional microbial community structure and stress responses in environments at all levels have tremendous implications for our fundamental understanding of hydrobiogeochemical processes and the potential for making bioremediation breakthroughs and illuminating the ‘black box’.

  14. Practical Solutions for the Design of Accelerated In Situ Bioremediation

    NASA Astrophysics Data System (ADS)

    Zhang, M.; Yoshikawa, M.; Takeuchi, M.; Komai, T.

    2010-12-01

    bioremediation, a combination of natural migration with pressurized injection and/or other approaches, like electro-migration, for stimulating mass transport could be necessary depending on the hydraulic properties, like porosity and permeability of a stratum.

  15. Timing the onset of sulfate reduction over multiple subsurface acetate amendments by measurement and modeling of sulfur isotope fractionation.

    PubMed

    Druhan, Jennifer L; Steefel, Carl I; Molins, Sergi; Williams, Kenneth H; Conrad, Mark E; DePaolo, Donald J

    2012-08-21

    Stable isotope fractionations of sulfur are reported for three consecutive years of acetate-enabled uranium bioremediation at the US Department of Energy's Rifle Integrated Field Research Challenge (IFRC) site. The data show a previously undocumented decrease in the time between acetate addition and the onset of sulfate reducing conditions over subsequent amendments, from 20 days in the 2007 experiment to 4 days in the 2009 experiment. Increased sulfide concentrations were observed at the same time as δ(34)S of sulfate enrichment in the first year, but in subsequent years elevated sulfide was detected up to 15 days after increased δ(34)S of sulfate. A biogeochemical reactive transport model is developed which explicitly incorporates the stable isotopes of sulfur to simulate fractionation during the 2007 and 2008 amendments. A model based on an initially low, uniformly distributed population of sulfate reducing bacteria that grow and become spatially variable with time reproduces measured trends in solute concentration and δ(34)S, capturing the change in onset of sulfate reduction in subsequent years. Our results demonstrate a previously unrecognized hysteretic effect in the spatial distribution of biomass growth during stimulated subsurface bioremediation. PMID:22834766

  16. Expression of acetate permease-like (apl) genes in subsurface communities of Geobacter species under fluctuating acetate concentrations

    SciTech Connect

    Elifantz, H.; N'Guessan, L.A.; Mouser, P.J.; Williams, K H.; Wilkins, M J.; Risso, C.; Holmes, D.E.; Long, P.E.; Lovley, D.R.

    2010-03-01

    The addition of acetate to uranium-contaminated aquifers in order to stimulate the growth and activity of Geobacter species that reduce uranium is a promising in situ bioremediation option. Optimizing this bioremediation strategy requires that sufficient acetate be added to promote Geobacter species growth. We hypothesized that under acetate-limiting conditions, subsurface Geobacter species would increase the expression of either putative acetate symporters genes (aplI and aplII). Acetate was added to a uranium-contaminated aquifer (Rifle, CO) in two continuous amendments separated by 5 days of groundwater flush to create changing acetate concentrations. While the expression of aplI in monitoring well D04 (high acetate) weakly correlated with the acetate concentration over time, the transcript levels for this gene were relatively constant in well D08 (low acetate). At the lowest acetate concentrations during the groundwater flush, the transcript levels of aplII were the highest. The expression of aplII decreased 2-10-fold upon acetate reintroduction. However, the overall instability of acetate concentrations throughout the experiment could not support a robust conclusion regarding the role of apl genes in response to acetate limitation under field conditions, in contrast to previous chemostat studies, suggesting that the function of a microbial community cannot be inferred based on lab experiments alone.

  17. Expression of Acetate Permease-like (apl) Genes in Subsurface Communities of Geobacter Species Under Fluctuating Acetate Concentrations

    SciTech Connect

    Elifantz, H; N'Guessan, A L; Mouser, Paula; Williams, Kenneth H; Wilkins, Michael J; Risso, Carla; Holmes, Dawn; Long, Philip E; Lovley, Derek R

    2010-09-01

    The addition of acetate to uranium-contaminated aquifers in order to stimulate the growth and activity of Geobacter species that reduce uranium is a promising in situ bioremediation option. Optimizing this bioremediation strategy requires that sufficient acetate be added to promote Geobacter species growth. We hypothesized that under acetate-limiting conditions, subsurface Geobacter species would increase the expression of either putative acetate symporters genes (aplI and aplII). Acetate was added to a uranium-contaminated aquifer (Rifle, CO) in two continuous amendments separated by 5 days of groundwater flush to create changing acetate concentrations. While the expression of aplI in monitoring well D04 (high acetate) weakly correlated with the acetate concentration over time, the transcript levels for this gene were relatively constant in well D08 (low acetate). At the lowest acetate concentrations during the groundwater flush, the transcript levels of aplII were the highest. The expression of aplII decreased 2–10-fold upon acetate reintroduction. However, the overall instability of acetate concentrations throughout the experiment could not support a robust conclusion regarding the role of apl genes in response to acetate limitation under field conditions, in contrast to previous chemostat studies, suggesting that the function of a microbial community cannot be inferred based on lab experiments alone.

  18. In situ bioremediation in Europe

    SciTech Connect

    Porta, A.; Young, J.K.; Molton, P.M.

    1993-06-01

    Site remediation activity in Europe is increasing, even if not at the forced pace of the US. Although there is a better understanding of the benefits of bioremediation than of other approaches, especially about in situ bioremediation of contaminated soils, relatively few projects have been carried out full-scale in Europe or in the US. Some engineering companies and large industrial companies in Europe are investigating bioremediation and biotreatment technologies, in some cases to solve their internal waste problems. Technologies related to the application of microorganisms to the soil, release of nutrients into the soil, and enhancement of microbial decontamination are being tested through various additives such as surfactants, ion exchange resins, limestone, or dolomite. New equipment has been developed for crushing and mixing or injecting and sparging the microorganisms, as have new reactor technologies (e.g., rotating aerator reactors, biometal sludge reactors, and special mobile containers for simultaneous storage, transportation, and biodegradation of contaminated soil). Some work has also been done with immobilized enzymes to support and restore enzymatic activities related to partial or total xenobiotic decontamination. Finally, some major programs funded by public and private institutions confirm that increasing numbers of firms have a working interest in bioremediation.

  19. TESTING BIOREMEDIATION IN THE FIELD

    EPA Science Inventory

    An operational definition for success of in situ bioremediation at field scale includes meeting regulatory goals for ground water quality in a timely fashion at a predictable cost. urrent practice for site characterization does not adequately define the amount of contamination su...

  20. Laboratory method used for bioremediation

    DOEpatents

    Carman, M. Leslie; Taylor, Robert T.

    2000-01-01

    An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

  1. ANAEROBIC BIOREMEDIATION OF CHLORINATED ETHENES

    EPA Science Inventory

    The failure of what have been termed convential methods to reclaim contaminated environmental media has over the years lead to the interest and development of alternative technologies. One of these technologies is bioremediation, or the utilization of microbial agents to reduce ...

  2. Key Factors Controlling the Applicability and Efficiency of Bioremediation of Chlorinated Ethenes In Situ

    NASA Astrophysics Data System (ADS)

    Zhang, M.; Yoshikawa, M.; Takeuchi, M.; Komai, T.

    2012-12-01

    Bioremediation has been considered as one of environmentally friendly and cost effective approaches for cleaning up the sites polluted by organic contaminants, such as chlorinated ethenes. Although bioremediation, in its widest sense, is not new, and many researches have been performed on bioremediation of different kinds of pollutants, an effective design and implication of in situ bioremediation still remains a challenging problem because of the complexity. Many factors may affect the applicability and efficiency of bioremediation of chlorinated ethenes in situ, which include the type and concentration of contaminants, biological, geological and hydro-geological conditions of the site, physical and chemical characteristics of groundwater and soils to be treated, as well as the constraints in engineering. In this presentation, an overview together with a detailed discussion on each factor will be provided. The influences of individual factors are discussed using the data obtained or cited from different sites and experiments, and thus under different environmental conditions. The results of this study illustrated that 1) the establishment of microbial consortium is of crucial importance for a complete degradation of chlorinated ethenes, 2) in situ control of favorable conditions for increasing microbial activities for bio-degradation through a designed pathway is the key to success, 3) the focus of a successful remediation system is to design an effective delivery process that is capable of producing adequate amendment mixing of contaminant-degrading bacteria, appropriate concentrations of electron acceptors, electron donors, and microbial nutrients in the subsurface treatment area.

  3. Enrichment of specific protozoan populations during in situ bioremediation of uranium-contaminated groundwater.

    PubMed

    Holmes, Dawn E; Giloteaux, Ludovic; Williams, Kenneth H; Wrighton, Kelly C; Wilkins, Michael J; Thompson, Courtney A; Roper, Thomas J; Long, Philip E; Lovley, Derek R

    2013-07-01

    The importance of bacteria in the anaerobic bioremediation of groundwater polluted with organic and/or metal contaminants is well recognized and in some instances so well understood that modeling of the in situ metabolic activity of the relevant subsurface microorganisms in response to changes in subsurface geochemistry is feasible. However, a potentially significant factor influencing bacterial growth and activity in the subsurface that has not been adequately addressed is protozoan predation of the microorganisms responsible for bioremediation. In field experiments at a uranium-contaminated aquifer located in Rifle, CO, USA, acetate amendments initially promoted the growth of metal-reducing Geobacter species, followed by the growth of sulfate reducers, as observed previously. Analysis of 18S rRNA gene sequences revealed a broad diversity of sequences closely related to known bacteriovorous protozoa in the groundwater before the addition of acetate. The bloom of Geobacter species was accompanied by a specific enrichment of sequences most closely related to the ameboid flagellate, Breviata anathema, which at their peak accounted for over 80% of the sequences recovered. The abundance of Geobacter species declined following the rapid emergence of B. anathema. The subsequent growth of sulfate-reducing Peptococcaceae was accompanied by another specific enrichment of protozoa, but with sequences most similar to diplomonadid flagellates from the family Hexamitidae, which accounted for up to 100% of the sequences recovered during this phase of the bioremediation. These results suggest a prey-predator response with specific protozoa responding to increased availability of preferred prey bacteria. Thus, quantifying the influence of protozoan predation on the growth, activity and composition of the subsurface bacterial community is essential for predictive modeling of in situ uranium bioremediation strategies. PMID:23446832

  4. Enrichment of specific protozoan populations during in situ bioremediation of uranium-contaminated groundwater

    PubMed Central

    Holmes, Dawn E; Giloteaux, Ludovic; Williams, Kenneth H; Wrighton, Kelly C; Wilkins, Michael J; Thompson, Courtney A; Roper, Thomas J; Long, Philip E; Lovley, Derek R

    2013-01-01

    The importance of bacteria in the anaerobic bioremediation of groundwater polluted with organic and/or metal contaminants is well recognized and in some instances so well understood that modeling of the in situ metabolic activity of the relevant subsurface microorganisms in response to changes in subsurface geochemistry is feasible. However, a potentially significant factor influencing bacterial growth and activity in the subsurface that has not been adequately addressed is protozoan predation of the microorganisms responsible for bioremediation. In field experiments at a uranium-contaminated aquifer located in Rifle, CO, USA, acetate amendments initially promoted the growth of metal-reducing Geobacter species, followed by the growth of sulfate reducers, as observed previously. Analysis of 18S rRNA gene sequences revealed a broad diversity of sequences closely related to known bacteriovorous protozoa in the groundwater before the addition of acetate. The bloom of Geobacter species was accompanied by a specific enrichment of sequences most closely related to the ameboid flagellate, Breviata anathema, which at their peak accounted for over 80% of the sequences recovered. The abundance of Geobacter species declined following the rapid emergence of B. anathema. The subsequent growth of sulfate-reducing Peptococcaceae was accompanied by another specific enrichment of protozoa, but with sequences most similar to diplomonadid flagellates from the family Hexamitidae, which accounted for up to 100% of the sequences recovered during this phase of the bioremediation. These results suggest a prey–predator response with specific protozoa responding to increased availability of preferred prey bacteria. Thus, quantifying the influence of protozoan predation on the growth, activity and composition of the subsurface bacterial community is essential for predictive modeling of in situ uranium bioremediation strategies. PMID:23446832

  5. Enrichment of specific protozoan populations during in situ bioremediation of uranium-contaminated groundwater

    SciTech Connect

    Holmes, Dawn; Giloteaux, L.; Williams, Kenneth H.; Wrighton, Kelly C.; Wilkins, Michael J.; Thompson, Courtney A.; Roper, Thomas J.; Long, Philip E.; Lovley, Derek

    2013-07-28

    The importance of bacteria in the anaerobic bioremediation of groundwater polluted with organic and/or metal contaminants is well-recognized and in some instances so well understood that modeling of the in situ metabolic activity of the relevant subsurface microorganisms in response to changes in subsurface geochemistry is feasible. However, a potentially significant factor influencing bacterial growth and activity in the subsurface that has not been adequately addressed is protozoan predation of the microorganisms responsible for bioremediation. In field experiments at a uranium-contaminated aquifer located in Rifle, CO, acetate amendments initially promoted the growth of metal-reducing Geobacter species followed by the growth of sulfate-reducers, as previously observed. Analysis of 18S rRNA gene sequences revealed a broad diversity of sequences closely related to known bacteriovorous protozoa in the groundwater prior to the addition of acetate. The bloom of Geobacter species was accompanied by a specific enrichment of sequences most closely related to the amoeboid flagellate, Breviata anathema, which at their peak accounted for over 80% of the sequences recovered. The abundance of Geobacter species declined following the rapid emergence of B. anathema. The subsequent growth of sulfate-reducing Peptococcaceae was accompanied by another specific enrichment of protozoa, but with sequences most similar to diplomonadid flagellates from the family Hexamitidae, which accounted for up to 100% of the sequences recovered during this phase of the bioremediation. These results suggest a prey-predator response with specific protozoa responding to increased availability of preferred prey bacteria. Thus, quantifying the influence of protozoan predation on the growth, activity, and composition of the subsurface bacterial community is essential for predictive modeling of in situ uranium bioremediation strategies.

  6. Bioremediation of Metals and Radionuclides: What It Is and How It Works (2nd Edition)

    SciTech Connect

    Palmisano, Anna; Hazen, Terry

    2003-09-30

    insoluble salt in the sediment. In other cases, the opposite occurs--the solubility of the altered species increases, increasing the mobility of the contaminant and allowing it to be more easily flushed from the environment. Both of these kinds of transformations present opportunities for bioremediation of metals and radionuclides--either to lock them in place, or to accelerate their removal. DOE's goal is to reduce the risk and related exposure to ground water, sediment, and soil contamination at Department of Energy facilities. Subsurface bioremediation of metals and radionuclides at the site of contamination (in situ bioremediation) is not yet in widespread use. However, successful in situ applications of bioremediation to petroleum products and chlorinated solvents provide experience from which scientists can draw. Taken together, the accomplishments in these areas have led scientists and engineers to be optimistic about applying this technology to the mixtures of metals and radionuclides that are found at some of the most contaminated DOE sites. This primer examines some of the basic microbial and chemical processes that are a part of bioremediation, specifically the bioremediation of metals and radionuclides. The primer is divided into six sections, with the information in each building on that of the previous. The sections include features that highlight topics of interest and provide background information on specific biological and chemical processes and reactions. The first section briefly examines the scope of the contamination problem at DOE facilities. The second section gives a summary of some of the most commonly used bioremediation technologies, including successful in situ and ex situ techniques. The third discusses chemical and physical properties of metals and radionuclides found in contaminant mixtures at DOE sites, including solubility and the most common oxidation states in which these materials are found. The fourth section is an overview of the basic

  7. Integration of Genome-Scale Metabolic Nodels of Iron-Reducing Bacteria With Subsurface Flow and Geochemical Reactive Transport Models

    NASA Astrophysics Data System (ADS)

    Scheibe, T. D.; Mahadevan, R.; Fang, Y.; Garg, S.; Long, P. E.; Lovley, D. M.

    2008-12-01

    Several field and laboratory experiments have demonstrated that the growth and activity of iron-reducing bacteria can be stimulated in many subsurface environments by amendment of groundwater with a soluble electron donor. Under strong iron-reducing conditions, these organisms mediate reactions that can impact a wide range of subsurface contaminants including chlorinated hydrocarbons, metals, and radionuclides. Therefore there is strong interest in in-situ bioremediation as a potential technology for cleanup of contaminated aquifers. To evaluate and design bioremediation systems, as well as to evaluate the viability of monitored natural attenuation as an alternative, quantitative models of biogeochemically reactive transport are needed. To date, most such models represent microbial activity in terms of kinetic rate (e.g., Monod- type) formulations. Such models do not account for fundamental changes in microbial functionality (such as utilization of alternative respiratory pathways) that occur as the result of spatial and temporal variations in the geochemical environment experienced by microorganisms. Constraint-based genome-scale in silico models of microbial metabolism present an alternative to simplified rate formulations that provide flexibility to account for changes in microbial function in response to local geochemical conditions. We have developed and applied a methodology for coupling a constraint-based in silico model of Geobacter sulfurreducens with a conventional model of groundwater flow, transport, and geochemical reaction. Two uses of the in silico model are tested: 1) incorporation of modified microbial growth yield coefficients based on the in silico model, and 2) variation of reaction rates in a reactive transport model based on in silico modeling of a range of local geochemical conditions. Preliminary results from this integrated model will be presented.

  8. Integrated Geophysical Measurements for Bioremediation Monitoring: Combining Spectral Induced Polarization, Nuclear Magnetic Resonance and Magnetic Methods

    SciTech Connect

    Keating, Kristina; Slater, Lee; Ntarlagiannis, Dimitris; Williams, Kenneth H.

    2015-02-24

    This documents contains the final report for the project "Integrated Geophysical Measurements for Bioremediation Monitoring: Combining Spectral Induced Polarization, Nuclear Magnetic Resonance and Magnetic Methods" (DE-SC0007049) Executive Summary: Our research aimed to develop borehole measurement techniques capable of monitoring subsurface processes, such as changes in pore geometry and iron/sulfur geochemistry, associated with remediation of heavy metals and radionuclides. Previous work has demonstrated that geophysical method spectral induced polarization (SIP) can be used to assess subsurface contaminant remediation; however, SIP signals can be generated from multiple sources limiting their interpretation value. Integrating multiple geophysical methods, such as nuclear magnetic resonance (NMR) and magnetic susceptibility (MS), with SIP, could reduce the ambiguity of interpretation that might result from a single method. Our research efforts entails combining measurements from these methods, each sensitive to different mineral forms and/or mineral-fluid interfaces, providing better constraints on changes in subsurface biogeochemical processes and pore geometries significantly improving our understanding of processes impacting contaminant remediation. The Rifle Integrated Field Research Challenge (IFRC) site was used as a test location for our measurements. The Rifle IFRC site is located at a former uranium ore-processing facility in Rifle, Colorado. Leachate from spent mill tailings has resulted in residual uranium contamination of both groundwater and sediments within the local aquifer. Studies at the site include an ongoing acetate amendment strategy, native microbial populations are stimulated by introduction of carbon intended to alter redox conditions and immobilize uranium. To test the geophysical methods in the field, NMR and MS logging measurements were collected before, during, and after acetate amendment. Next, laboratory NMR, MS, and SIP measurements

  9. Microbes safely, effectively bioremediate oil field pits

    SciTech Connect

    Shaw, B. ); Block, C.S. ); Mills, C.H. )

    1995-01-30

    Natural and augmented bioremediation provides a safe, environmental, fast, and effective solution for removing hydrocarbon stains from soil. In 1992, Amoco sponsored a study with six bioremediation companies, which evaluated 14 different techniques. From this study, Amoco continued using Environmental Protection Co.'s (EPC) microbes for bioremediating more than 145 sites near Farmington, NM. EPC's microbes proved effective on various types of hydrocarbon molecules found in petroleum stained soils from heavy crude and paraffin to volatiles such as BTEX (benzene, toluene, ethylbenzene, xylene) compounds. Controlled laboratory tests have shown that these microbes can digest the hydrocarbon molecules with or without free oxygen present. It is believed that this adaptation gives these microbes their resilience. The paper describes the bioremediation process, environmental advantages, in situ and ex situ bioremediation, goals of bioremediation, temperature effects, time, cost, and example sites that were treated.

  10. Effective sensing approach for assessment and monitoring of in-situ biodegradation in a subsurface environment

    NASA Astrophysics Data System (ADS)

    Li, Dong X.

    1999-02-01

    Rapid assessment and monitoring of biological conditions in a subsurface environment is becoming more and more important as bioremediation approaches become widely used in environmental cleanup. Remediation monitoring is also more challenging for in-situ remedial approaches, such as bioventing, biosparging, or passive bioremediation, where conventional 'inlet' and 'outlet' monitoring can no longer be applied. A sensing approach using subsurface chemical sensors offers a cost- effective alternative for remediation monitoring. Additional benefits of deploying subsurface sensors include continuous and unattended measurement with minimum disturbance to the subsurface condition. In a series of field studies, an electrochemical oxygen sensor, a non-dispersive infrared (NDIR) carbon dioxide sensor, and two hydrocarbons sensors were employed for monitoring in-situ bioremediation of petroleum hydrocarbon contaminated soils. Biodegradation rates were effectively measured through an in-situ respiration measurement using subsurface oxygen and carbon dioxide sensors. The high sensitivity of the carbon dioxide sensor to small change in the concentration enables rapid respiration measurements. Subsurface hydrocarbon sensors offer a means to monitor the progress of remediation and the migration of contaminant vapors during the remediation. The chemical sensors tested are clearly cost effective for remediation monitoring. The strengths of oxygen and carbon dioxide sensors are complimentary to each other. Strengths and limitations of different hydrocarbon sensors were also noted. Balancing cost and performance of sensors is crucial for environmental remediation application.

  11. DESIGN AND OPERATION OF A HORIZONTAL WELL, IN SITU BIOREMEDIATION SYSTEM

    EPA Science Inventory

    A large field demonstration using nutrient addition to stimulate insitu anaerobic bioremediation of chlorinated solvent contaminated soil and ground water was performed at the former U.S. Department of Energy Pinellas Plant in Largo, Florida, from January through June, 1997. Ins...

  12. LABORATORY EVALUATION OF OIL SPILL BIOREMEDIATION PRODUCTS IN SALT AND FRESHWATER SYSTEMS

    EPA Science Inventory

    Ten oil spill bioremediation products were tested in the laboratory for their ability to enhance biodegradation of weathered Alaskan North Slope crude oil in both fresh and salt-water media. The products included: nutrients to stimulate inoculated microorganisms, nutrients plus a...

  13. NATURAL BIOREMEDIATION PERSPECTIVE FOR BTX CONTAMINATED GROUNDWATER IN BRAZIL: EFFECT OF ETHANOL (R823420)

    EPA Science Inventory

    Abstract

    Natural bioremediation, the use of indigenous microorganisms to degrade hazardous substances within aquifers without engineered stimulation, shows great promise as a cost-effective approach to hydrocarbon plume management. This technique requires thorough site...

  14. In situ vadose zone bioremediation.

    PubMed

    Höhener, Patrick; Ponsin, Violaine

    2014-06-01

    Contamination of the vadose zone with various pollutants is a world-wide problem, and often technical or economic constraints impose remediation without excavation. In situ bioremediation in the vadose zone by bioventing has become a standard remediation technology for light spilled petroleum products. In this review, focus is given on new in situ bioremediation strategies in the vadose zone targeting a variety of other pollutants such as perchlorate, nitrate, uranium, chromium, halogenated solvents, explosives and pesticides. The techniques for biostimulation of either oxidative or reductive degradation pathways are presented, and biotransformations to immobile pollutants are discussed in cases of non-degradable pollutants. Furthermore, research on natural attenuation in the vadose zone is presented. PMID:24863890

  15. Integrative analysis of the interactions between Geobacter spp. and sulfate-reducing bacteria during uranium bioremediation

    NASA Astrophysics Data System (ADS)

    Barlett, M.; Zhuang, K.; Mahadevan, R.; Lovley, D. R.

    2011-11-01

    Enhancing microbial U(VI) reduction with the addition of organic electron donors is a promising strategy for immobilizing uranium in contaminated groundwaters, but has yet to be optimized because of a poor understanding of the factors controlling the growth of various microbial communities during bioremediation. In previous field trials in which acetate was added to the subsurface, there were two distinct phases: an initial phase in which acetate-oxidizing, U(VI)-reducing Geobacter predominated and U(VI) was effectively reduced and a second phase in which acetate-oxidizing sulfate reducing bacteria (SRB) predominated and U(VI) reduction was poor. The interaction of Geobacter and SRB was investigated both in sediment incubations that mimicked in situ bioremediation and with in silico metabolic modeling. In sediment incubations, Geobacter grew quickly but then declined in numbers as the microbially reducible Fe(III) was depleted whereas the SRB grow more slowly and reached dominance after 30-40 days. Modeling predicted a similar outcome. Additional modeling in which the relative initial percentages of the Geobacter and SRB were varied indicated that there was little to no competitive interaction between Geobacter and SRB when acetate was abundant. Further simulations suggested that the addition of Fe(III) would revive the Geobacter, but have little to no effect on the SRB. This result was confirmed experimentally. The results demonstrate that it is possible to predict the impact of amendments on important components of the subsurface microbial community during groundwater bioremediation. The finding that Fe(III) availability, rather than competition with SRB, is the key factor limiting the activity of Geobacter during in situ uranium bioremediation will aid in the design of improved uranium bioremediation strategies.

  16. Integrative analysis of Geobacter spp. and sulfate-reducing bacteria during uranium bioremediation

    NASA Astrophysics Data System (ADS)

    Barlett, M.; Zhuang, K.; Mahadevan, R.; Lovley, D.

    2012-03-01

    Enhancing microbial U(VI) reduction with the addition of organic electron donors is a promising strategy for immobilizing uranium in contaminated groundwaters, but has yet to be optimized because of a poor understanding of the factors controlling the growth of various microbial communities during bioremediation. In previous field trials in which acetate was added to the subsurface, there were two distinct phases: an initial phase in which acetate-oxidizing, U(VI)-reducing Geobacter predominated and U(VI) was effectively reduced and a second phase in which acetate-oxidizing sulfate reducing bacteria (SRB) predominated and U(VI) reduction was poor. The interaction of Geobacter and SRB was investigated both in sediment incubations that mimicked in situ bioremediation and with in silico metabolic modeling. In sediment incubations, Geobacter grew quickly but then declined in numbers as the microbially reducible Fe(III) was depleted whereas the SRB grow more slowly and reached dominance after 30-40 days. Modeling predicted a similar outcome. Additional modeling in which the relative initial percentages of the Geobacter and SRB were varied indicated that there was little to no competitive interaction between Geobacter and SRB when acetate was abundant. Further simulations suggested that the addition of Fe(III) would revive the Geobacter, but have little to no effect on the SRB. This result was confirmed experimentally. The results demonstrate that it is possible to predict the impact of amendments on important components of the subsurface microbial community during groundwater bioremediation. The finding that Fe(III) availability, rather than competition with SRB, is the key factor limiting the activity of Geobacter during in situ uranium bioremediation will aid in the design of improved uranium bioremediation strategies.

  17. Change in Bacterial Community Structure during In Situ Biostimulation of Subsurface Sediment Cocontaminated with Uranium and Nitrate

    PubMed Central

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

    2004-01-01

    Previous studies have demonstrated that metal-reducing microorganisms can effectively promote the precipitation and removal of uranium from contaminated groundwater. Microbial communities were stimulated in the acidic subsurface by pH neutralization and addition of an electron donor to wells. In single-well push-pull tests at a number of treated sites, nitrate, Fe(III), and uranium were extensively reduced and electron donors (glucose, ethanol) were consumed. Examination of sediment chemistry in cores sampled immediately adjacent to treated wells 3.5 months after treatment revealed that sediment pH increased substantially (by 1 to 2 pH units) while nitrate was largely depleted. A large diversity of 16S rRNA gene sequences were retrieved from subsurface sediments, including species from the α, β, δ, and γ subdivisions of the class Proteobacteria, as well as low- and high-G+C gram-positive species. Following in situ biostimulation of microbial communities within contaminated sediments, sequences related to previously cultured metal-reducing δ-Proteobacteria increased from 5% to nearly 40% of the clone libraries. Quantitative PCR revealed that Geobacter-type 16S rRNA gene sequences increased in biostimulated sediments by 1 to 2 orders of magnitude at two of the four sites tested. Evidence from the quantitative PCR analysis corroborated information obtained from 16S rRNA gene clone libraries, indicating that members of the δ-Proteobacteria subdivision, including Anaeromyxobacter dehalogenans-related and Geobacter-related sequences, are important metal-reducing organisms in acidic subsurface sediments. This study provides the first cultivation-independent analysis of the change in metal-reducing microbial communities in subsurface sediments during an in situ bioremediation experiment. PMID:15294831

  18. Biofouling effects on in situ TCE bioremediation by phenol utilizers

    SciTech Connect

    MacDonald, T.R.; Kitanidis, P.K.

    1995-12-31

    In situ bioremediation involves stimulating the growth of bacteria within the contaminated region of an aquifer to break down the contaminants. This large bacteria population often can have the unwanted effect of clogging the porous media. The clogging reduces the porosity and the hydraulic conductivity of the soil. These hydrodynamic changes can affect the flow of groundwater used to deliver nutrients to the bacteria in the contaminated region of the aquifer. The authors developed a mathematical model to study the impact of biofouling on a recirculation well flow system used to mix nutrients with contaminated groundwater. The insights gained from this examination can aid in designing a system to minimize biofouling problems.

  19. Characterization of anaerobic chloroethene-dehalogenating activity in several subsurface sediments

    SciTech Connect

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

    1996-11-01

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

  20. Bioremediation of a Large Chlorinated Solvent Plume, Dover AFB, DE

    SciTech Connect

    Bloom, Aleisa C

    2015-01-01

    Bioremediation of a Large Chlorinated Solvent Plume, Dover AFB, DE Aleisa Bloom, (Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA) Robert Lyon (bob.lyon@aecom.com), Laurie Stenberg, and Holly Brown (AECOM, Germantown, Maryland, USA) ABSTRACT: Past disposal practices at Dover Air Force Base (AFB), Delaware, created a large solvent plume called Area 6 (about 1 mile long, 2,000 feet wide, and 345 acres). The main contaminants are PCE, TCE, and their degradation products. The remedy is in-situ accelerated anaerobic bioremediation (AAB). AAB started in 2006 and is focusing on source areas and downgradient plume cores. Direct-push injections occurred in source areas where contamination is typically between 5 and 20 feet below ground surface. Lower concentration dissolved-phased contamination is present downgradient at 35 and 50 feet below ground surface. Here, permanent injection/extraction wells installed in transects perpendicular to the flow of groundwater are used to apply AAB. The AAB substrate is a mix of sodium lactate, emulsified vegetable oil, and nutrients. After eight years, dissolved contaminant mass within the main 80-acre treatment area has been reduced by over 98 percent. This successful application of AAB has stopped the flux of contaminants to the more distal portions of the plume. While more time is needed for effects to be seen in the distal plume, AAB injections will soon cease, and the remedy will transition to natural attenuation. INTRODUCTION Oak Ridge National Laboratory Environmental Science Division (ORNL) and AECOM (formerly URS Corporation) have successfully implemented in situ accelerated anaerobic bioremediation (AAB) to remediate chlorinated solvent contamination in a large, multi-sourced groundwater plume at Dover Air Force Base (AFB). AAB has resulted in significant reductions of dissolved phase chlorinated solvent concentrations. This plume, called Area 6, was originally over 1 mile in length and over 2,000 feet wide (Figure 1

  1. Preliminary technology report for Southern Sector bioremediation

    SciTech Connect

    Brigmon, R.L.; White, R.; Hazen, T.C.; Jones, D.; Berry, C.

    1997-06-01

    This project was designed to demonstrate the potential of intrinsic bioremediation and phytoremediation in the Southern Sector of the A/M-Area at the Savannah River Site. A subsurface plume of trichloroethylene (TCE) and perchloroethylene (PCE) is present in the Lost Lake aquifer upgradient of the study site and is predicted to impact the area at some point in the future. The surface area along the Lost lake aquifer seep line where the plume is estimated to emerge was identified. Ten sites along the seep line were selected for biological, chemical, and contaminant treatability analyses. A survey was undertaken in this area to to quantify the microbial and plant population known to be capable of remediating TCE and PCE. The current groundwater quality upgradient and downgradient of the zone of influence was determined. No TCE or PCE was found in the soils or surface water from the area tested at this time. A TCE biodegradation treatability test was done on soil from the 10 selected locations. From an initial exposure of 25 ppm of TCE, eight of the samples biodegraded up to 99.9 percent of all the compound within 6 weeks. This biodegradation of TCE appears to be combination of aerobic and anaerobic microbial activity as intermediates that were detected in the treatability test include vinyl chloride (VC) and the dichloroethenes (DCE) 1,2-cis-dichloroethylene and 1,1-dichloroethylene. The TCE biological treatability studies were combines with microbiological and chemical analyses. The soils were found through immunological analysis with direct fluorescent antibodies (DFA) and microbiological analysis with direct fluorescent antibodies (DFA) and microbiological analysis to have a microbial population of methanotrophic bacteria that utilize the enzyme methane monooxygenase (MMO) and cometabolize TCE.

  2. BIOREMEDIATION OF OIL-CONTAMINATED FINE SEDIMENTS.

    EPA Science Inventory

    Bioremediation of oil contamination has been shown to be effective for cobble and sandy shorelines. To assess the operational limitations of this technology, this project studied its potential to treat buried oil in fine sediments. The effectiveness of bioremediation by nutrient ...

  3. 7 CFR 3201.63 - Bioremediation materials.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Bioremediation materials. 3201.63 Section 3201.63... Designated Items § 3201.63 Bioremediation materials. (a) Definition. Dry or liquid solutions (including those containing bacteria or other microbes but not including sorbent materials) used to clean oil, fuel, and...

  4. Intrinsic bioremediation of landfills interim report

    SciTech Connect

    Brigmon, R.L.; Fliermans, C.B.

    1997-07-14

    Intrinsic bioremediation is a risk management option that relies on natural biological and physical processes to contain the spread of contamination from a source. Evidence is presented in this report that intrinsic bioremediation is occurring at the Sanitary Landfill is fundamental to support incorportion into a Corrective Action Plan (CAP).

  5. An evaluation of in-situ bioremediation processes

    SciTech Connect

    Cole, L.L.; Rashidi, M.

    1996-08-01

    Remediation of petroleum hydrocarbons in groundwater was the primary focus in the initial application of in-situ bioremediation which, from its development in the 1970s, has grown to become one of the most promising technologies for the degradation of a wide variety of organic contaminants. The degradation of contaminants in subsurface soils is the current new focus of the technology. While the need for improvements in the technology does exist, the indisputable fact remains that this technology is by far the least expensive and that it has the capability to provide long term reduced levels of contaminants or long term complete remediation of contaminated sites. The aim of this paper is to disclose pertinent information related to current conditions and current feelings in the area of new research, novel applications, new government regulations, and an overview of new topics on the horizon that relate to the overall technology.

  6. In Situ Bioremediation of Chlorinated Ethenes in Hydraulically-Tight Sediments: Challenges and Limitations

    NASA Astrophysics Data System (ADS)

    Zhang, M.; Yoshikawa, M.; Takeuchi, M.; Komai, T.

    2011-12-01

    Chlorinated ethenes, like perchloroethene (PCE) and trichloroethene (TCE), have been widely used by many industries, especially in developed countries like Japan. Because of their wide applications, lack of proper regulation, poor handing, storage and disposal practices in the past, chlorinated ethenes have become a type of the most prevalent contaminants for soils and groundwater pollution. For the sake of their degradability, bioremediation has been considered as a potentially cost-effective and environmentally friendly approach for cleanup of chlorinated ethenes in situ. In this presentation, we briefly overview the status of soil and groundwater pollution, the recent amendment of the Soil Contamination Countermeasures Act in Japan, comparison between the bioremediation and other techniques like pump and treat, and the mechanisms of reductive dechlorination, direct oxidation and co-metabolism of chlorinated ethenes. We then introduce and discuss some recent challenges and advancements in in-situ bioremediation including technologies for accelerating bio-degradation of chlorinated ethenes, technologies for assessing diffusive properties of dissolved hydrogen in hydraulically-tight soil samples, and combination of bioremediation with other techniques like electro-kinetic approach. Limiting factors that may cause incomplete remediation and/or ineffectiveness of bioremediation are examined from biochemical, geochemical and hydro-geological aspects. This study reconfirmed and illustrated that: 1) The key factor for an effective bioremediation is how to disperse a proper accelerating agent throughout the polluted strata, 2) The effective diffusion coefficient of dissolved hydrogen in geologic media is relatively big and is almost independent on their permeability, and 3) To effectively design and perform an accelerated bioremediation, a combination of natural migration with pressurized injection and/or other approaches, like electro-migration, for stimulating mass

  7. Bioremediation of oil contaminated beach material in Prince William Sound, Alaska

    SciTech Connect

    Pritchard, P.H. )

    1990-01-01

    The Office of Research and Development within the Environmental Protection Agency has been evaluating bioremediation to help clean up beaches in Alaska's Prince William Sound following the March 24, 1989 Exxon Valdez oil spill. Bioremediation techniques have been used elsewhere to accelerate the natural biological degradation of environmental contaminants. The purpose of EPA's project was to determine the best bioremediation approach for the oil contaminated shoreline of Prince William Sound. The major portion of the EPA study, therefore, has been a field demonstration to determine if nutrient (fertilizer) addition to contaminated beaches will effectively stimulate hydrocarbon breakdown by indigenous bacteria. Concurrently, a monitoring program has been instituted to check for any possible adverse environmental effects from nutrient addition. Techniques of applying nutrient mixtures to the beaches have been investigated.

  8. Microbiological and Geochemical Heterogeneity in an In Situ Uranium Bioremediation Field Site

    PubMed Central

    Vrionis, Helen A.; Anderson, Robert T.; Ortiz-Bernad, Irene; O'Neill, Kathleen R.; Resch, Charles T.; Peacock, Aaron D.; Dayvault, Richard; White, David C.; Long, Philip E.; Lovley, Derek R.

    2005-01-01

    The geochemistry and microbiology of a uranium-contaminated subsurface environment that had undergone two seasons of acetate addition to stimulate microbial U(VI) reduction was examined. There were distinct horizontal and vertical geochemical gradients that could be attributed in large part to the manner in which acetate was distributed in the aquifer, with more reduction of Fe(III) and sulfate occurring at greater depths and closer to the point of acetate injection. Clone libraries of 16S rRNA genes derived from sediments and groundwater indicated an enrichment of sulfate-reducing bacteria in the order Desulfobacterales in sediment and groundwater samples. These samples were collected nearest the injection gallery where microbially reducible Fe(III) oxides were highly depleted, groundwater sulfate concentrations were low, and increases in acid volatile sulfide were observed in the sediment. Further down-gradient, metal-reducing conditions were present as indicated by intermediate Fe(II)/Fe(total) ratios, lower acid volatile sulfide values, and increased abundance of 16S rRNA gene sequences belonging to the dissimilatory Fe(III)- and U(VI)-reducing family Geobacteraceae. Maximal Fe(III) and U(VI) reduction correlated with maximal recovery of Geobacteraceae 16S rRNA gene sequences in both groundwater and sediment; however, the sites at which these maxima occurred were spatially separated within the aquifer. The substantial microbial and geochemical heterogeneity at this site demonstrates that attempts should be made to deliver acetate in a more uniform manner and that closely spaced sampling intervals, horizontally and vertically, in both sediment and groundwater are necessary in order to obtain a more in-depth understanding of microbial processes and the relative contribution of attached and planktonic populations to in situ uranium bioremediation. PMID:16204552

  9. Effectiveness of U(VI) Bioremediation by DMRB in Dual Porosity Soils Explored via Numerical Modeling

    NASA Astrophysics Data System (ADS)

    Rotter, B. E.; Barry, A.; Gerhard, J. I.

    2006-12-01

    The use of naturally present dissimilatory metal reducing bacteria (DMRB) is a promising bioremediation option for uranium-contaminated sites. DMRB activity is typically stimulated by introducing an organic carbon source into the subsurface, resulting in bioreduction of highly soluble U(VI) to immobile U(IV). While this process has been demonstrated in the laboratory for simple systems, it is important to understand how its effectiveness is influenced by a variety of natural and engineered processes expected in typical applications. Biogeochemical reactive transport models provide a valuable means for investigating the performance of and parameter sensitivities of these complex systems. A new one-dimensional model for DMRB bioreduction of U(VI) was developed in PHREEQC. The model includes multiple redox processes, U(VI) sorption, and both single and dual porosity domains. The model was applied to a variety of real-site parameterized scenarios in order to explore the impact of (i) modeling approaches, (ii) expected natural variability inherent in porous media systems, and (iii) engineering options for implementation. Examples of the first include diverse approaches to modeling active biomass (1st order vs. non-growth Monod vs. Monod with growth; multiple microbial communities vs. a single community). Examples of the second include diffusion-limited mass transfer between the advective flow region and the immobile micro-matrix region through variations in region porosities, bioreduction rates and mass transfer rate coefficients, as well as aquifer mineralogy. Examples of the third include organic carbon injection regimes (quantity and duration) and their impact on U(IV) reoxidation. These suites of simulations provide valuable insight into key system sensitivities that will guide further model development and upscaling to field scale.

  10. Microbial communities in contaminated sediments, associated with bioremediation of uranium to submicromolar levels

    SciTech Connect

    Cardenas, Erick; Wu, Weimin; Leigh, Mary Beth; Carley, Jack M; Carroll, Sue L; Gentry, Terry; Luo, Jian; Watson, David B; Gu, Baohua; Ginder-Vogel, Matthew A.; Kitanidis, Peter K.; Jardine, Philip M; Zhou, Jizhong; Criddle, Craig; Marsh, Terence; Tiedje, James M.

    2008-03-01

    Microbial enumeration, 16S rRNA gene clone libraries, and chemical analysis were used to evaluate the in situ biological reduction and immobilization of uranium(VI) in a long-term experiment (more than 2 years) conducted at a highly uranium-contaminated site (up to 60 mg/liter and 800 mg/kg solids) of the U.S. Department of Energy in Oak Ridge, TN. Bioreduction was achieved by conditioning groundwater above ground and then stimulating growth of denitrifying, Fe(III)-reducing, and sulfate-reducing bacteria in situ through weekly injection of ethanol into the subsurface. After nearly 2 years of intermittent injection of ethanol, aqueous U levels fell below the U.S. Environmental Protection Agency maximum contaminant level for drinking water and groundwater (<30 {micro}g/liter or 0.126 {micro}M). Sediment microbial communities from the treatment zone were compared with those from a control well without biostimulation. Most-probable-number estimations indicated that microorganisms implicated in bioremediation accumulated in the sediments of the treatment zone but were either absent or in very low numbers in an untreated control area. Organisms belonging to genera known to include U(VI) reducers were detected, including Desulfovibrio, Geobacter, Anaeromyxobacter, Desulfosporosinus, and Acidovorax spp. The predominant sulfate-reducing bacterial species were Desulfovibrio spp., while the iron reducers were represented by Ferribacterium spp. and Geothrix spp. Diversity-based clustering revealed differences between treated and untreated zones and also within samples of the treated area. Spatial differences in community structure within the treatment zone were likely related to the hydraulic pathway and to electron donor metabolism during biostimulation.

  11. Microbial Communities in Contaminated Sediments, Associated with Bioremediation of Uranium to Submicromolar Levels▿

    PubMed Central

    Cardenas, Erick; Wu, Wei-Min; Leigh, Mary Beth; Carley, Jack; Carroll, Sue; Gentry, Terry; Luo, Jian; Watson, David; Gu, Baohua; Ginder-Vogel, Matthew; Kitanidis, Peter K.; Jardine, Philip M.; Zhou, Jizhong; Criddle, Craig S.; Marsh, Terence L.; Tiedje, James M.

    2008-01-01

    Microbial enumeration, 16S rRNA gene clone libraries, and chemical analysis were used to evaluate the in situ biological reduction and immobilization of uranium(VI) in a long-term experiment (more than 2 years) conducted at a highly uranium-contaminated site (up to 60 mg/liter and 800 mg/kg solids) of the U.S. Department of Energy in Oak Ridge, TN. Bioreduction was achieved by conditioning groundwater above ground and then stimulating growth of denitrifying, Fe(III)-reducing, and sulfate-reducing bacteria in situ through weekly injection of ethanol into the subsurface. After nearly 2 years of intermittent injection of ethanol, aqueous U levels fell below the U.S. Environmental Protection Agency maximum contaminant level for drinking water and groundwater (<30 μg/liter or 0.126 μM). Sediment microbial communities from the treatment zone were compared with those from a control well without biostimulation. Most-probable-number estimations indicated that microorganisms implicated in bioremediation accumulated in the sediments of the treatment zone but were either absent or in very low numbers in an untreated control area. Organisms belonging to genera known to include U(VI) reducers were detected, including Desulfovibrio, Geobacter, Anaeromyxobacter, Desulfosporosinus, and Acidovorax spp. The predominant sulfate-reducing bacterial species were Desulfovibrio spp., while the iron reducers were represented by Ferribacterium spp. and Geothrix spp. Diversity-based clustering revealed differences between treated and untreated zones and also within samples of the treated area. Spatial differences in community structure within the treatment zone were likely related to the hydraulic pathway and to electron donor metabolism during biostimulation. PMID:18456853

  12. Hydrogen as an Indicator to Assess Biological Activity During Trace-Metal Bioremediation

    SciTech Connect

    Jaffe, Peter R.; Lovley, Derek; Komlos, John; Brown, Derick

    2004-03-17

    The design and operation of a trace-metal or radionuclide bioremediation scheme requires that specific redox conditions be achieved at given zones of an aquifer for a pre-determined duration. Tools are therefore needed to identify and quantify the terminal electron accepting processes (TEAPs) that are being achieved during bioremediation in an aquifer, and that this be done at a high spatial resolution. Dissolved hydrogen (H{sub 2}) concentrations have been shown to correlate with specific TEAPs during bioremediation in an aquifer (Table 1). Theoretical analysis has shown that these steady-state hydrogen levels are solely dependent upon the physiological parameters of the hydrogen-consuming microorganisms, with hydrogen concentrations increasing as each successive TEAP yields less energy for bacterial growth. The assumptions for this statement may not hold during a bioremediation scheme in which an organic substrate is injected into the subsurface and where organisms may consume hydrogen and carbon simultaneously. This research examines the effects of simultaneous hydrogen and carbon utilization through obtaining kinetic parameters of both hydrogen and carbon consumption under iron reducing conditions in batch experiments. A dual-donor model was formulated and compared to flow-through column experiments.

  13. Monitoring Genetic and Metabolic Potential for In-Site Bioremediation: Mass Spectrometry

    SciTech Connect

    Buchanan, M.V.

    2000-07-20

    A number of DOE sites are contaminated with mixtures of dense non-aqueous phase liquids (DNAPLs) such as carbon tetrachloride, chloroform, perchloroethylene, and trichloroethylene. At many of these sites, in situ microbial bioremediation is an attractive strategy for cleanup, since it has the potential to degrade DNAPLs in situ without the need for pump-and-treat or soil removal procedures, and without producing toxic byproducts. A rapid screening method to determine broad range metabolic and genetic potential for contaminant degradation would greatly reduce the cost and time involved in assessment for in situ bioremediation, as well as for monitoring ongoing bioremediation treatment. The objective of this project was the development of mass-spectrometry-based methods to screen for genetic potential for both assessment and monitoring of in situ bioremediation of DNAPLs. These methods were designed to provide more robust and routine methods for DNA-based characterization of the genetic potential of subsurface microbes for degrading pollutants. Specifically, we sought to (1) Develop gene probes that yield information equivalent to conventional probes, but in a smaller size that is more amenable to mass spectrometric detection, (2) Pursue improvements to matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) methodology in order to allow its more general application to gene probe detection, and (3) Increase the throughput of microbial characterization by integrating gene probe preparation, purification, and MALDI-MS analysis.

  14. Mineral transformation and biomass accumulation associated with uranium bioremediation at Rifle, Colorado

    SciTech Connect

    Li, L.; Steefel, C.I.; Williams, K.H.; Wilkins, M.J.; Hubbard, S.S.

    2009-04-20

    Injection of organic carbon into the subsurface as an electron donor for bioremediation of redox-sensitive contaminants like uranium often leads to mineral transformation and biomass accumulation, both of which can alter the flow field and potentially bioremediation efficacy. This work combines reactive transport modeling with a column experiment and field measurements to understand the biogeochemical processes and to quantify the biomass and mineral transformation/accumulation during a bioremediation experiment at a uranium contaminated site near Rifle, Colorado. We use the reactive transport model CrunchFlow to explicitly simulate microbial community dynamics of iron and sulfate reducers, and their impacts on reaction rates. The column experiment shows clear evidence of mineral precipitation, primarily in the form of calcite and iron monosulfide. At the field scale, reactive transport simulations suggest that the biogeochemical reactions occur mostly close to the injection wells where acetate concentrations are highest, with mineral precipitate and biomass accumulation reaching as high as 1.5% of the pore space. This work shows that reactive transport modeling coupled with field data can be an effective tool for quantitative estimation of mineral transformation and biomass accumulation, thus improving the design of bioremediation strategies.

  15. Laboratory modeling, field study, and numerical simulation of bioremediation of petroleum contaminants

    SciTech Connect

    Livingston, R.J.; Islam, M.R.

    1999-01-01

    The use of bioremediation as an alternative remediation technology is fast becoming the technique of choice among many environmental professionals. This method offers substantial benefits not found in other remediation processes. Bioremediation is very cost effective, nondestructive, relatively uncomplicated in implementing, requires nonspecialized equipment, and can be extremely effective in removing recalcitrant petroleum hydrocarbons. This study researched the availability of viable microbial populations in the arid climate in South Dakota. Exponential growth of the bacteria and the ability of bacteria to degrade long-chain hydrocarbons indicated that healthy populations do exist and could be used to mineralize organic hydrocarbons. Experimental results indicated that bioremediation can be effectively enhanced in landfills as well as in the subsurface using a supply of harmless nutrients. The biodegradation rate can be further enhanced with the use of edible surfactant that helped disperse the petroleum products. Also, the use of hydrogen peroxide enhanced the oxygen availability and increased the degradation rate. Interestingly, the bacterial growth rate was found to be high in difficult-to-biodegrade contaminants, such as waste oil. A numerical simulation program was also developed that describes the bacterial growth in the subsurface along with the reduction in substrate (contamination). Results from this program were found to be consistent with laboratory results.

  16. Rehabilitation of oil polluted soils by bioremediation

    NASA Astrophysics Data System (ADS)

    Dumitru, Mihail; Parvan, Lavinia; Cioroianu, Mihai; Carmen, Sirbu; Constantin, Carolina

    2015-04-01

    In Romania about 50,000 ha are polluted with oil and/or brine. The main sources of pollution are the different activities using petroleum products: extraction, transport, treatment, refining and distribution. Taking into acoount the large areas and the cost per unit area, bioremediation was tested as a method of rehabilitation. To stimulate the performance of the bioremediation process for a polluted soil (luvisol) by 3% oil, different methods were tested: -application of a bacterial inoculum consisting of species of the Pseudomonas and Arthrobacter genera;- application of two types of absorbent materials, 16 t/ha peat and 16, respectively, 32 kg/ha Zeba (starch-based polymer, superabsorbent); -mineral fertilization with N200P200K200 and 5 different liquid fertilizer based on potassium humates extracted from lignite in a NPK matrix with micronutrients and added monosaccharides (4 and 8%). After 45 days from the treatment (60 days from pollution) the following observations have been noticed: • the application of only bacterial inoculum had no significant effect on the degradation of petroleum hydrocarbons; • the use of 650 l/ha AH-SH fertilizer (potassium humate in a NPK matrix) led to a 47% decrease of TPH (total petroleum hydrocarbons); • the application of 16 t/ha peat, together with the bacterial inoculum and the AH-SG2 liquid fertilizer (containing humates of potassium in a NPK matrix with microelements and 8% monosaccharides, in which the nitrogen is amide form) led to a 50% decrease of the TPH content; • the application of 16 kg/ha Zeba absorbent together with bacterial inoculum and 650 l/ha AH-SG1 liquid fertilizer (containing humates of potassium in a NPK matrix with microelements and 4% monosaccharide in which the nitrogen is in amide form) led to a 57% decrease of the TPH content; • the application of 32 kg/ha Zeba absorbent, together with the AH-SG2 fertilizer, led to a 58% decrease of the TPH content.

  17. Model-based Analysis of Mixed Uranium(VI) Reduction by Biotic and Abiotic Pathways During in Situ Bioremediation

    SciTech Connect

    Zhao, Jiao; Scheibe, Timothy D.; Mahadevan, Radhakrishnan

    2013-10-24

    Uranium bioremediation has emerged as a potential strategy of cleanup of radionuclear contamination worldwide. An integrated geochemical & microbial community model is a promising approach to predict and provide insights into the bioremediation of a complicated natural subsurface. In this study, an integrated column-scale model of uranium bioremediation was developed, taking into account long-term interactions between biotic and abiotic processes. It is also combined with a comprehensive thermodynamic analysis to track the fate and cycling of biogenic species. As compared with other bioremediation models, the model increases the resolution of the connection of microbial community to geochemistry and establishes direct quantitative correlation between overall community evolution and geochemical variation, thereby accurately predicting the community dynamics under different sedimentary conditions. The thermodynamic analysis examined a recently identified homogeneous reduction of U(VI) by Fe(II) under dynamic sedimentary conditions across time and space. It shows that the biogenic Fe(II) from Geobacter metabolism can be removed rapidly by the biogenic sulphide from sulfate reducer metabolism, hence constituting one of the reasons that make the abiotic U(VI) reduction thermodynamically infeasible in the subsurface. Further analysis indicates that much higher influent concentrations of both Fe(II) and U(VI) than normal are required to for abiotic U(VI) reduction to be thermodynamically feasible, suggesting that the abiotic reduction cannot be an alternative to the biotic reduction in the remediation of uranium contaminated groundwater.

  18. Genetic analysis of stress responses in soil bacteria for enhanced bioremediation of mixed contaminants. 1997 annual progress report

    SciTech Connect

    Wong, K.K.

    1997-06-01

    'To provide increased knowledge of stress responses of indigenous microbes at contaminated sites as well as using microbes as molecular probes for monitoring the performance and effectiveness of bioremediation, the authors propose to identify the stress-inducible genes and promoters from two soil bacteria, Deinococcus radiodurans and Sphingomonas F199. These organisms represent two phylogenetically distinct groups of soil bacteria, each of which has specific features of interest for bioremediation. D. radiodurans exhibits high resistance to external stress; F199 is a deep subsurface (Savannah River Site) organism with unique degradative capabilities. Research Statement To realize the full potential of bioremediation, an understanding of microbial community and individual bacterial responses to the stresses encountered at contaminated sites is needed. Knowledge about genetic responses of soil and subsurface bacteria to environmental stresses, which include low nutrients, low oxygen, and mixed pollutants, will allow extrapolation of basic principles to field applications either using indigenous bacteria or genetically engineered microorganisms. Defining bacterial responses to those stresses presents an opportunity for improving bioremediation strategies, and should contribute to environmental management and restoration actions that would reduce the cost and time required to achieve DOE''s cleanup goals.'

  19. Use of Biotracer Tests to Evaluate the Feasibility of In-Situ Bioremediation

    NASA Astrophysics Data System (ADS)

    Lourenso, F. J.; Brusseau, M. L.

    2001-12-01

    In-situ bioremediation of organic compounds in the subsurface is increasing in popularity. A biodegradation tracer test, also known as biotracer test, is one approach to determine the feasibility of practicing this method. This test involves conducting a tracer experiment with one or more compounds whose biodegradation properties are known. The mass recovery and transport of the biotracers are compared to a non-biodegradable, conservative tracer to measure the biological activity of the target zone. Field experiments were conducted at three sites. All three sites were contaminated with non-aqueous phase liquids. Biotracers were also used to investigate the response of the system to the addition of perturbations, e.g. the addition of oxygen. The results from these field experiments suggest biotracers are a promising method for characterizing in-situ bioremediation.

  20. Bioremediation of metals and inorganic compounds

    SciTech Connect

    Alleman, B.C.; Leeson, A.

    1999-11-01

    Bioremediation has been a problematic alternative for remediation of metals and inorganic compound contamination. Unlike organic contaminants, which often can be broken down by biological processes into relatively harmless metabolites and byproducts, metals are elemental. Further, metals and their salts often have an inhibitory effect on biological activity. However, despite these potential pitfalls, there has been progress recently in applying bioremediation technologies to metals and inorganics. This volume encompasses topics such as lead solubility reduction, chromium reduction, denitrification, volatilization of selenium in soils, metals recovery from acid mine drainage, and even the possibility of applying artificial neural network technology to aid in bioremediation.

  1. In situ bioremediation using horizontal wells

    SciTech Connect

    1995-04-01

    In Situ Bioremediation (ISB), which is the term used in this report for Gaseous Nutrient Injection for In Situ Bioremediation, remediates soils and ground water contaminated with volatile organic compounds (VOCs) both above and below the water table. ISB involves injection of air and nutrients (sparging and biostimulation) into the ground water and vacuum extraction to remove .VOCs from the vadose zone concomitant with biodegradation of VOCs. The innovation is in the combination of 3 emerging technologies, air stripping, horizontal wells, and bioremediation via gaseous nutrient injection with a baseline technology, soil vapor extraction, to produce a more efficient in situ remediation system.

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

    SciTech Connect

    Lovley, Derek R.

    2012-10-31

    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.

  3. Biosurfactant-enhanced soil bioremediation

    SciTech Connect

    Kosaric, N.; Lu, G.; Velikonja, J.

    1995-12-01

    Bioremediation of soil contaminated with organic chemicals is a viable alternative method for clean-up and remedy of hazardous waste sites. The final objective in this approach is to convert the parent toxicant into a readily biodegradable product which is harmless to human health and/or the environment. Biodegradation of hydrocarbons in soil can also efficiently be enhanced by addition or in-situ production of biosufactants. It was generally observed that the degradation time was shortened and particularly the adaptation time for the microbes. More data from our laboratories showed that chlorinated aromatic compounds, such as 2,4-dichlorophenol, a herbicide Metolachlor, as well as naphthalene are degraded faster and more completely when selected biosurfactants are added to the soil. More recent data demonstrated an enhanced biodegradation of heavy hydrocarbons in petrochemical sludges, and in contaminated oil when biosurfactants were present or were added prior to the biodegradation process.

  4. BIOREMEDIATED SOIL VENTING OF LIGHT HYDROCARBONS

    EPA Science Inventory

    The effectiveness and feasibility of bioremediated soil venting of light hydrocarbons in the unsaturated zone was investigated. Degradation mechanics were considered as a one dimensional balance of storage, linear sorption, vertical advection, and Michaelis-Menton kinetics. he re...

  5. Bioremediation of wastewater using microalgae

    NASA Astrophysics Data System (ADS)

    Chalivendra, Saikumar

    Population expansion and industrial development has deteriorated the quality of freshwater reservoirs around the world and has caused freshwater shortages in certain areas. Discharge of industrial effluents containing toxic heavy metals such as Cd and Cr into the environment have serious impact on human, animal and aquatic life. In order to solve these problems, the present study was focused on evaluating and demonstrating potential of microalgae for bioremediation of wastewater laden with nitrogen (N) in the form of nitrates, phosphorous (P) in the form of phosphates, chromium (Cr (VI)) and cadmium (Cd (II)). After screening several microalgae, Chlorella vulgaris and algae taken from Pleasant Hill Lake were chosen as candidate species for this study. The viability of the process was demonstrated in laboratory bioreactors and various experimental parameters such as contact time, initial metal concentration, algae concentration, pH and temperature that would affect remediation rates were studied. Based on the experimental results, correlations were developed to enable customizing and designing a commercial Algae based Wastewater Treatment System (AWTS). A commercial AWTS system that can be easily customized and is suitable for integration into existing wastewater treatment facilities was developed, and capital cost estimates for system including installation and annual operating costs were determined. The work concludes that algal bioremediation is a viable alternate technology for treating wastewater in an economical and sustainable way when compared to conventional treatment processes. The annual wastewater treatment cost to remove N,P is ~26x lower and to remove Cr, Cd is 7x lower than conventional treatment processes. The cost benefit analysis performed shows that if this technology is implemented at industrial complexes, Air Force freight and other Department of Defense installations with wastewater treatment plants, it could lead to millions of dollars in

  6. DEMONSTRATION BULLETIN: NEW YORK STATE MULTI-VENDOR BIOREMEDIATION - ENSR CONSULTING AND ENGINEERING/LARSEN ENGINEERS EX-SITU BIOVAULT

    EPA Science Inventory

    The ENSR Biovault Treatment Process is an ex-situ bioremediation technology for the treatment of organic contaminated soils. Contaminated soils placed in specially designed soil piles, referred to as biovaults, are remediated by stimulating the indigenous soil microbes to prolife...

  7. Effectiveness of bioremediation in reducing toxicity in oiled intertidal sediments

    SciTech Connect

    Lee, K.; Tremblay, G.H.; Siron, R.

    1995-12-31

    A 123-day field study was conducted with in situ enclosures to compare the effectiveness of bioremediation strategies based in inorganic and organic fertilizer additions to accelerate the biodegradation rates and reduce the toxicity of Venture{trademark} condensate stranded within sand-beach sediments. Comparison of the two fertilizer formulations with identical nitrogen and phosphorus concentrations showed that the organic fertilizer stimulated bacterial productivity within the oiled sediments to the greatest extent. However, detailed chemical analysis indicated that inorganic fertilizer additions were the most effective in enhancing condensate biodegradation rates. The Microtox{reg_sign} Solid-Phase Test (SPT) bioassay was determined to be sensitive to Venture Condensate in laboratory tests. Subsequent application of this procedure to oiled sediment in the field showed a reduction in sediment toxicity over time. However, the Microtox{reg_sign} bioassay procedure did not identify significant reductions in sediment toxicity following bioremediation treatment. An observed increase in toxicity following periodic additions of the organic fertilizer was attributed to rapid biodegradation rates of the fertilizer, which resulted in the production of toxic metabolic products.

  8. Noncompetitive microbial diversity patterns in soils: their causes and implications for bioremediation

    SciTech Connect

    James M. Tiedje; Jizhong Zhou; Anthony Palumbo; Nathaniel Ostrom; Terence L. Marsh

    2007-07-05

    This funding provided support for over nine years of research on the structure and function of microbial communities in subsurface environments. The overarching goal during these years was to understand the impact of mixed contaminants, particularly heavy metals like uranium, on the structure and function of microbial communities. In addition we sought to identify microbial populations that were actively involved in the reduction of metals because these species of bacteria hold the potential for immobilizing soluble metals moving in subsurface water. Bacterial mediated biochemical reduction of metals like uranium, technetium and chromium, greatly reduces their mobility through complexation and precipitation. Hence, by taking advantage of natural metabolic capabilities of subsurface microbial populations it is possible to bioremediate contaminated subsurface environments with a cost-effective in situ approach. Towards this end we have i.) identified bacterial populations that have thrived under the adverse conditions at the contaminated FRC site, ii.) phylogenetically identified populations that respond to imposed remediation conditions at the FRC, iii.) used metagenomics to begin a reconstruction of the metabolic web in a contaminated subsurface zone, iv.) investigated the metal reducing attributes of a Gram-positive spore forming rod also capable of dechlorination.

  9. A Functional Genomic Approach to Chlorinated Ethenes Bioremediation

    NASA Astrophysics Data System (ADS)

    Lee, P. K.; Brodie, E. L.; MacBeth, T. W.; Deeb, R. A.; Sorenson, K. S.; Andersen, G. L.; Alvarez-Cohen, L.

    2007-12-01

    With the recent advances in genomic sciences, a knowledge-based approach can now be taken to optimize the bioremediation of trichloroethene (TCE). During the bioremediation of a heterogeneous subsurface, it is vital to identify and quantify the functionally important microorganisms present, characterize the microbial community and measure their physiological activity. In our field experiments, quantitative PCR (qPCR) was coupled with reverse-transcription (RT) to analyze both copy numbers and transcripts expressed by the 16S rRNA gene and three reductive dehalogenase (RDase) genes as biomarkers of Dehalococcoides spp. in the groundwater of a TCE-DNAPL site at Ft. Lewis (WA) that was serially subjected to biostimulation and bioaugmentation. Genes in the Dehalococcoides genus were targeted as they are the only known organisms that can completely dechlorinate TCE to the innocuous product ethene. Biomarker quantification revealed an overall increase of more than three orders of magnitude in the total Dehalococcoides population and quantification of the more liable and stringently regulated mRNAs confirmed that Dehalococcoides spp. were active. Parallel with our field experiments, laboratory studies were conducted to explore the physiology of Dehalococcoides isolates in order to develop relevant biomarkers that are indicative of the metabolic state of cells. Recently, we verified the function of the nitrogenase operon in Dehalococcoides sp. strain 195 and nitrogenase-encoding genes are ideal biomarker targets to assess cellular nitrogen requirement. To characterize the microbial community, we applied a high-density phylogenetic microarray (16S PhyloChip) that simultaneous monitors over 8,700 unique taxa to track the bacterial and archaeal populations through different phases of treatment. As a measure of species richness, 1,300 to 1,520 taxa were detected in groundwater samples extracted during different stages of treatment as well as in the bioaugmentation culture. We

  10. Bioremediation Potential of Terrestrial Fuel Spills †

    PubMed Central

    Song, Hong-Gyu; Wang, Xiaoping; Bartha, Richard

    1990-01-01

    A bioremediation treatment that consisted of liming, fertilization, and tilling was evaluated on the laboratory scale for its effectiveness in cleaning up a sand, a loam, and a clay loam contaminated at 50 to 135 mg g of soil−1 by gasoline, jet fuel, heating oil, diesel oil, or bunker C. Experimental variables included incubation temperatures of 17, 27, and 37°C; no treatment; bioremediation treatment; and poisoned evaporation controls. Hydrocarbon residues were determined by quantitative gas chromatography or, in the case of bunker C, by residual weight determination. Four-point depletion curves were obtained for the described experimental variables. In all cases, the disappearance of hydrocarbons was maximal at 27°C and in response to bioremediation treatment. Poisoned evaporation controls underestimated the true biodegradation contribution, but nevertheless, they showed that biodegradation makes only a modest contribution to gasoline disappearance from soil. Bunker C was found to be structurally recalcitrant, with close to 80% persisting after 1 year of incubation. The three medium distillates, jet fuel, heating oil, and diesel oil, increased in persistence in the listed order but responded well to bioremediation treatment under all test conditions. With bioremediation treatment, it should be possible to reduce hydrocarbons to insignificant levels in contaminated soils within one growing season. PMID:16348139

  11. Diverse Metabolic Capacities of Fungi for Bioremediation.

    PubMed

    Deshmukh, Radhika; Khardenavis, Anshuman A; Purohit, Hemant J

    2016-09-01

    Bioremediation refers to cost-effective and environment-friendly method for converting the toxic, recalcitrant pollutants into environmentally benign products through the action of various biological treatments. Fungi play a major role in bioremediation owing to their robust morphology and diverse metabolic capacity. The review focuses on different fungal groups from a variety of habitats with their role in bioremediation of different toxic and recalcitrant compounds; persistent organic pollutants, textile dyes, effluents from textile, bleached kraft pulp, leather tanning industries, petroleum, polyaromatic hydrocarbons, pharmaceuticals and personal care products, and pesticides. Bioremediation of toxic organics by fungi is the most sustainable and green route for cleanup of contaminated sites and we discuss the multiple modes employed by fungi for detoxification of different toxic and recalcitrant compounds including prominent fungal enzymes viz., catalases, laccases, peroxidases and cyrochrome P450 monooxygeneses. We have also discussed the recent advances in enzyme engineering and genomics and research being carried out to trace the less understood bioremediation pathways. PMID:27407289

  12. Monitoring Genetic and Metabolic Potential for in situ Bioremediation: Mass Spectrometry

    SciTech Connect

    Buchanan, Michelle V.

    2000-12-31

    A number of DOE sites are contaminated with mixtures of dense non-aqueous phase liquids (DNAPLs) such as carbon tetrachloride, chloroform, perchloroethylene, and trichloroethylene. At many of these sites, in situ microbial bioremediation is an attractive strategy for cleanup, since it has the potential to degrade DNAPLs in situ without the need for pump-and-treat or soil removal procedures, and without producing toxic byproducts. A rapid screening method to determine broad range metabolic and genetic potential for contaminant degradation would greatly reduce the cost and time involved in assessment for in situ bioremediation, as well as for monitoring ongoing bioremediation treatment. The objective of this project was the development of mass-spectrometry-based methods to screen for genetic potential for both assessment and monitoring of in situ bioremediation of DNAPLs. These methods were designed to provide more robust and routine methods for DNA based characterization of th e genetic potential of subsurface microbes for degrading pollutants. Specifically, we sought to (1) Develop gene probes that yield information equivalent to conventional probes, but in a smaller size that is more amenable to mass spectrometric detection, (2) Pursue improvements to matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) methodology in order to allow its more general application to gene probe detection, (3) Increase the throughput of microbial characterization by integrating gene probe preparation, purification, and MALDI-MS analysis. Effective decision-making regarding remediation strategies requires information on the contaminants present and the relevant hydrogeology. However, it also should include information on the relevant bacterial populations present and the biodegradative processes they carry out. For each site at which bioremediation is considered, it is necessary to determine whether sufficient intrinsic degradative capability is present to suggest

  13. Bioremediation of marine oil spills: when and when not--the Exxon Valdez experience.

    PubMed

    Atlas, Ronald; Bragg, James

    2009-03-01

    In this article we consider what we have learned from the Exxon Valdez oil spill (EVOS) in terms of when bioremediation should be considered and what it can accomplish. We present data on the state of oiling of Prince William Sound shorelines 18 years after the spill, including the concentration and composition of subsurface oil residues (SSOR) sampled by systematic shoreline surveys conducted between 2002 and 2007. Over this period, 346 sediment samples were analysed by GC-MS and extents of hydrocarbon depletion were quantified. In 2007 alone, 744 sediment samples were collected and extracted, and 222 were analysed. Most sediment samples from sites that were heavily oiled by the spill and physically cleaned and bioremediated between 1989 and 1991 show no remaining SSOR. Where SSOR does remain, it is for the most part highly weathered, with 82% of 2007 samples indicating depletion of total polycyclic aromatic hydrocarbon (Total PAH) of >70% relative to EVOS oil. This SSOR is sequestered in patchy deposits under boulder/cobble armour, generally in the mid-to-upper intertidal zone. The relatively high nutrient concentrations measured at these sites, the patchy distribution and the weathering state of the SSOR suggest that it is in a form and location where bioremediation likely would be ineffective at increasing the rate of hydrocarbon removal. PMID:21261915

  14. Field application of a genetically engineered microorganism for polycyclic aromatic hydrocarbon bioremediation process monitoring and control

    SciTech Connect

    Sayler, G.S.; Cox, C.D.; Ripp, S.; Nivens, D.E.; Werner, C.; Ahn, Y.; Matrubutham, U.; Burlage, R.

    1998-11-01

    On October 30, 1996, the US Environmental Protection Agency (EPA) commenced the first test release of genetically engineered microorganisms (GEMs) for use in bioremediation. The specific objectives of the investigation were multifaceted and include (1) testing the hypothesis that a GEM can be successfully introduced and maintained in a bioremediation process, (2) testing the concept of using, at the field scale, reporter organisms for direct bioremediation process monitoring and control, and (3) acquiring data that can be used in risk assessment decision making and protocol development for future field release applications of GEMs. The genetically engineered strain under investigation is Pseudomonas fluorescens strain HK44 (King et al., 1990). The original P. fluorescens parent strain was isolated from polycyclic aromatic hydrocarbon (PAH) contaminated manufactured gas plant soil. Thus, this bacterium is able to biodegrade naphthalene (as well as other substituted naphthalenes and other PAHs) and is able to function as a living bioluminescent reporter for the presence of naphthalene contamination, its bioavailability, and the functional process of biodegradation. A unique component of this field investigation was the availability of an array of large subsurface soil lysimeters. This article describes the experience associated with the release of a genetically modified microorganism, the lysimeter facility and its associated instrumentation, as well as representative data collected during the first eighteen months of operation.

  15. Deploying in situ bioremediation at the Hanford Site

    SciTech Connect

    Truex, M.J.; Johnson, C.D.; Newcomer, D.R.; Doremus, L.A.; Hooker, B.S.; Peyton, B.M.; Skeen, R.S.; Chilakapati, A.

    1994-11-01

    An innovative in-situ bioremediation technology was developed by Pacific Northwest Laboratory (PNL) to destroy nitrate and carbon tetrachloride (CC1{sub 4}) in the Hanford ground water. The goal of this in-situ treatment process is to stimulate native microorganisms to degrade nitrate and CCl{sub 4}. Nutrient solutions are distributed in the contaminated aquifer to create a biological treatment zone. This technology is being demonstrated at the US Department of Energy`s Hanford Site to provide the design, operating, and cost information needed to assess its effectiveness in contaminated ground water. The process design and field operations for demonstration of this technology are influenced by the physical, chemical, and microbiological properties observed at the site. A description of the technology is presented including the well network design, nutrient injection equipment, and means for controlling the hydraulics and microbial reactions of the treatment process.

  16. Enhanced bioremediation of oil spills in the sea.

    PubMed

    Ron, Eliora Z; Rosenberg, Eugene

    2014-06-01

    Hydrocarbon-degrading bacteria are ubiquitous in the sea, including hydrocarbonoclastic bacteria that utilize hydrocarbons almost exclusively as carbon and energy sources. However, the rates at which they naturally degrade petroleum following an oil spill appear to be too slow to prevent oil from reaching the shore and causing environmental damage, as has been documented in the Exxon Valdez and Gulf of Mexico disasters. Unfortunately, there is, at present, no experimentally demonstrated methodology for accelerating the degradation of hydrocarbons in the sea. The rate-limiting factor for petroleum degradation in the sea is availability of nitrogen and phosphorus. Oleophilic fertilizers, such as Inipol EAP 22 and urea-formaldehyde polymers, have stimulated hydrocarbon degradation on shorelines but are less effective in open systems. We suggest uric acid as a potentially useful fertilizer enhancing bioremediation at sea. PMID:24657912

  17. Functional environmental proteomics: elucidating the role of a c-type cytochrome abundant during uranium bioremediation.

    PubMed

    Yun, Jiae; Malvankar, Nikhil S; Ueki, Toshiyuki; Lovley, Derek R

    2016-02-01

    Studies with pure cultures of dissimilatory metal-reducing microorganisms have demonstrated that outer-surface c-type cytochromes are important electron transfer agents for the reduction of metals, but previous environmental proteomic studies have typically not recovered cytochrome sequences from subsurface environments in which metal reduction is important. Gel-separation, heme-staining and mass spectrometry of proteins in groundwater from in situ uranium bioremediation experiments identified a putative c-type cytochrome, designated Geobacter subsurface c-type cytochrome A (GscA), encoded within the genome of strain M18, a Geobacter isolate previously recovered from the site. Homologs of GscA were identified in the genomes of other Geobacter isolates in the phylogenetic cluster known as subsurface clade 1, which predominates in a diversity of Fe(III)-reducing subsurface environments. Most of the gscA sequences recovered from groundwater genomic DNA clustered in a tight phylogenetic group closely related to strain M18. GscA was most abundant in groundwater samples in which Geobacter sp. predominated. Expression of gscA in a strain of Geobacter sulfurreducens that lacked the gene for the c-type cytochrome OmcS, thought to facilitate electron transfer from conductive pili to Fe(III) oxide, restored the capacity for Fe(III) oxide reduction. Atomic force microscopy provided evidence that GscA was associated with the pili. These results demonstrate that a c-type cytochrome with an apparent function similar to that of OmcS is abundant when Geobacter sp. are abundant in the subsurface, providing insight into the mechanisms for the growth of subsurface Geobacter sp. on Fe(III) oxide and suggesting an approach for functional analysis of other Geobacter proteins found in the subsurface. PMID:26140532

  18. Bioremediation of Petroleum Hydrocarbon Contaminated Sites

    SciTech Connect

    Fallgren, Paul

    2009-03-30

    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

  19. Technical Basis for Assessing Uranium Bioremediation Performance

    SciTech Connect

    PE Long; SB Yabusaki; PD Meyer; CJ Murray; AL N’Guessan

    2008-04-01

    In situ bioremediation of uranium holds significant promise for effective stabilization of U(VI) from groundwater at reduced cost compared to conventional pump and treat. This promise is unlikely to be realized unless researchers and practitioners successfully predict and demonstrate the long-term effectiveness of uranium bioremediation protocols. Field research to date has focused on both proof of principle and a mechanistic level of understanding. Current practice typically involves an engineering approach using proprietary amendments that focuses mainly on monitoring U(VI) concentration for a limited time period. Given the complexity of uranium biogeochemistry and uranium secondary minerals, and the lack of documented case studies, a systematic monitoring approach using multiple performance indicators is needed. This document provides an overview of uranium bioremediation, summarizes design considerations, and identifies and prioritizes field performance indicators for the application of uranium bioremediation. The performance indicators provided as part of this document are based on current biogeochemical understanding of uranium and will enable practitioners to monitor the performance of their system and make a strong case to clients, regulators, and the public that the future performance of the system can be assured and changes in performance addressed as needed. The performance indicators established by this document and the information gained by using these indicators do add to the cost of uranium bioremediation. However, they are vital to the long-term success of the application of uranium bioremediation and provide a significant assurance that regulatory goals will be met. The document also emphasizes the need for systematic development of key information from bench scale tests and pilot scales tests prior to full-scale implementation.

  20. Strategies for chromium bioremediation of tannery effluent.

    PubMed

    Garg, Satyendra Kumar; Tripathi, Manikant; Srinath, Thiruneelakantan

    2012-01-01

    Bioremediation offers the possibility of using living organisms (bacteria, fungi, algae,or plants), but primarily microorganisms, to degrade or remove environmental contaminants, and transform them into nontoxic or less-toxic forms. The major advantages of bioremediation over conventional physicochemical and biological treatment methods include low cost, good efficiency, minimization of chemicals, reduced quantity of secondary sludge, regeneration of cell biomass, and the possibility of recover-ing pollutant metals. Leather industries, which extensively employ chromium compounds in the tanning process, discharge spent-chromium-laden effluent into nearby water bodies. Worldwide, chromium is known to be one of the most common inorganic contaminants of groundwater at pollutant hazardous sites. Hexavalent chromium poses a health risk to all forms of life. Bioremediation of chromium extant in tannery waste involves different strategies that include biosorption, bioaccumulation,bioreduction, and immobilization of biomaterial(s). Biosorption is a nondirected physiochemical interaction that occurs between metal species and the cellular components of biological species. It is metabolism-dependent when living biomass is employed, and metabolism-independent in dead cell biomass. Dead cell biomass is much more effective than living cell biomass at biosorping heavy metals, including chromium. Bioaccumulation is a metabolically active process in living organisms that works through adsorption, intracellular accumulation, and bioprecipitation mechanisms. In bioreduction processes, microorganisms alter the oxidation/reduction state of toxic metals through direct or indirect biological and chemical process(es).Bioreduction of Cr6+ to Cr3+ not only decreases the chromium toxicity to living organisms, but also helps precipitate chromium at a neutral pH for further physical removal,thus offering promise as a bioremediation strategy. However, biosorption, bioaccumulation, and

  1. Ceramic subsurface marker prototypes

    SciTech Connect

    Lukens, C.E.

    1985-05-02

    The client submitted 5 sets of porcelain and stoneware subsurface (radioactive site) marker prototypes (31 markers each set). The following were determined: compressive strength, thermal shock resistance, thermal crazing resistance, alkali resistance, color retention, and chemical resistance.

  2. Subsurface Microbiology and Biogeochemistry

    SciTech Connect

    Fredrickson, Jim K.; Fletcher, Madilyn

    2001-05-01

    Jim contributed a chapter to this book, in addition to co-editing it with Madilyn Fletcher. Fredrickson, J. K., and M. Fletcher. (eds.) 2001 Subsurface Microbiology and Biogeochemistry. Wiley-Liss, Inc., New York.

  3. Laboratory-scale in situ bioremediation in heterogeneous porous media: Biokinetics-limited scenario

    NASA Astrophysics Data System (ADS)

    Song, Xin; Hong, Eunyoung; Seagren, Eric A.

    2014-03-01

    Subsurface heterogeneities influence interfacial mass-transfer processes and affect the application of in situ bioremediation by impacting the availability of substrates to the microorganisms. However, for difficult-to-degrade compounds, and/or cases with inhibitory biodegradation conditions, slow biokinetics may also limit the overall bioremediation rate, or be as limiting as mass-transfer processes. In this work, a quantitative framework based on a set of dimensionless coefficients was used to capture the effects of the competing interfacial and biokinetic processes and define the overall rate-limiting process. An integrated numerical modeling and experimental approach was used to evaluate application of the quantitative framework for a scenario in which slow-biokinetics limited the overall bioremediation rate of a polycyclic aromatic hydrocarbon (naphthalene). Numerical modeling was conducted to simulate the groundwater flow and naphthalene transport and verify the system parameters, which were used in the quantitative framework application. The experiments examined the movement and biodegradation of naphthalene in a saturated, heterogeneous intermediate-scale flow cell with two layers of contrasting hydraulic conductivities. These experiments were conducted in two phases: Phase I, simulating an inhibited slow biodegradation; and Phase II, simulating an engineered bioremediation, with system perturbations selected to enhance the slow biodegradation rate. In Phase II, two engineered perturbations to the system were selected to examine their ability to enhance in situ biodegradation. In the first perturbation, nitrogen and phosphorus in excess of the required stoichiometric amounts were spiked into the influent solution to mimic a common remedial action taken in the field. The results showed that this perturbation had a moderate positive impact, consistent with slow biokinetics being the overall rate-limiting process. However, the second perturbation, which was to

  4. Laboratory-scale in situ bioremediation in heterogeneous porous media: biokinetics-limited scenario.

    PubMed

    Song, Xin; Hong, Eunyoung; Seagren, Eric A

    2014-03-01

    Subsurface heterogeneities influence interfacial mass-transfer processes and affect the application of in situ bioremediation by impacting the availability of substrates to the microorganisms. However, for difficult-to-degrade compounds, and/or cases with inhibitory biodegradation conditions, slow biokinetics may also limit the overall bioremediation rate, or be as limiting as mass-transfer processes. In this work, a quantitative framework based on a set of dimensionless coefficients was used to capture the effects of the competing interfacial and biokinetic processes and define the overall rate-limiting process. An integrated numerical modeling and experimental approach was used to evaluate application of the quantitative framework for a scenario in which slow-biokinetics limited the overall bioremediation rate of a polycyclic aromatic hydrocarbon (naphthalene). Numerical modeling was conducted to simulate the groundwater flow and naphthalene transport and verify the system parameters, which were used in the quantitative framework application. The experiments examined the movement and biodegradation of naphthalene in a saturated, heterogeneous intermediate-scale flow cell with two layers of contrasting hydraulic conductivities. These experiments were conducted in two phases: Phase I, simulating an inhibited slow biodegradation; and Phase II, simulating an engineered bioremediation, with system perturbations selected to enhance the slow biodegradation rate. In Phase II, two engineered perturbations to the system were selected to examine their ability to enhance in situ biodegradation. In the first perturbation, nitrogen and phosphorus in excess of the required stoichiometric amounts were spiked into the influent solution to mimic a common remedial action taken in the field. The results showed that this perturbation had a moderate positive impact, consistent with slow biokinetics being the overall rate-limiting process. However, the second perturbation, which was to

  5. Deep subsurface microbial processes

    USGS Publications Warehouse

    Lovley, D.R.; Chapelle, F.H.

    1995-01-01

    Information on the microbiology of the deep subsurface is necessary in order to understand the factors controlling the rate and extent of the microbially catalyzed redox reactions that influence the geophysical properties of these environments. Furthermore, there is an increasing threat that deep aquifers, an important drinking water resource, may be contaminated by man's activities, and there is a need to predict the extent to which microbial activity may remediate such contamination. Metabolically active microorganisms can be recovered from a diversity of deep subsurface environments. The available evidence suggests that these microorganisms are responsible for catalyzing the oxidation of organic matter coupled to a variety of electron acceptors just as microorganisms do in surface sediments, but at much slower rates. The technical difficulties in aseptically sampling deep subsurface sediments and the fact that microbial processes in laboratory incubations of deep subsurface material often do not mimic in situ processes frequently necessitate that microbial activity in the deep subsurface be inferred through nonmicrobiological analyses of ground water. These approaches include measurements of dissolved H2, which can predict the predominant microbially catalyzed redox reactions in aquifers, as well as geochemical and groundwater flow modeling, which can be used to estimate the rates of microbial processes. Microorganisms recovered from the deep subsurface have the potential to affect the fate of toxic organics and inorganic contaminants in groundwater. Microbial activity also greatly influences 1 the chemistry of many pristine groundwaters and contributes to such phenomena as porosity development in carbonate aquifers, accumulation of undesirably high concentrations of dissolved iron, and production of methane and hydrogen sulfide. Although the last decade has seen a dramatic increase in interest in deep subsurface microbiology, in comparison with the study of

  6. Microbial Studies Supporting Implementation of In Situ Bioremediation at TAN

    SciTech Connect

    Barnes, Joan Marie; Matthern, Gretchen Elise; Rae, Catherine; Ely, R. L.

    2000-11-01

    The Idaho National Engineering and Environmental Laboratory is evaluating in situ bioremediation of contaminated groundwater at its Test Area North Facility. To determine feasibility, microcosm and bioreactor studies were conducted to ascertain the ability of indigenous microbes to convert trichloroethene and dichloroethene to non-hazardous byproducts under aerobic and anaerobic conditions, and to measure the kinetics of microbial reactions associated with the degradation process. Microcosms were established from core samples and groundwater obtained from within the contaminant plume. These microcosms were amended with nutrients, under aerobic and anaerobic conditions, to identify electron donors capable of stimulating the degradation process. Results of the anaerobic microcosm studies showed that lactate, acetate and propionate amendments stimulated indigenous cell growth and functioned as effective substrates for reductive degradation of chloroethenes. Bioreactors inoculated with cultures from these anaerobic microcosms were operated under a batch mode for 42 days then converted to a fed-batch mode and operated at a 53-day hydraulic residence time. It was demonstrated that indigenous microbes capable of complete anaerobic reductive dechlorination are present in the subject well. It was also demonstrated that aerobic microbes capable of oxidizing chlorinated compounds produced by anaerobic reductive dechlorination are present. Kinetic data suggest that controlling the type and concentration of electron donors can increase trichlorethene conversion rates. In the event that complete mineralization of trichlorethene does not occur following stimulation, and anaerobic/aerobic treatment scheme is feasible.

  7. In situ detection of anaerobic alkane metabolites in subsurface environments

    PubMed Central

    Agrawal, Akhil; Gieg, Lisa M.

    2013-01-01

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

  8. Subsurface Contamination Control

    SciTech Connect

    Y. Yuan

    2001-12-12

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

  9. MTBE BIODEGRADATION AND BIOREMEDIATION (ROCKY GAP, MD)

    EPA Science Inventory

    MTBE contamination in ground water at gasoline spill sites can be treated with in situ aerobic bioremediation. All that is usually necessary is to provide sufficient oxygen to meet the oxygen demand of the fuel components in the ground water. The field scale performance of the ...

  10. MTBE BIODEGRADATION AND BIOREMEDIATION (ROCKY GAP, MD*)

    EPA Science Inventory

    MTBE contamination in ground water at gasoline spill sites can be treated with in situ aerobic bioremediation. All that is usually necessary is to provide sufficient oxygen to meet the oxygen demand of the fuel components in the ground water. The field scale performance of the ...

  11. BIOREMEDIATION AT WOOD-PRESERVING SITES

    EPA Science Inventory

    The removal of organic compounds from ground water during bioremediation at wood-preserving sites is a function of the stoichiometric demand for electron acceptors (oxygen, nitrate, and sulfate) to metabolize the organic contaminants and the supply of the electron acceptors in th...

  12. In situ microbial filter used for bioremediation

    DOEpatents

    Carman, M. Leslie; Taylor, Robert T.

    2000-01-01

    An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

  13. Potential of bioremediation for buried oil removal in beaches after an oil spill.

    PubMed

    Pontes, Joana; Mucha, Ana P; Santos, Hugo; Reis, Izabela; Bordalo, Adriano; Basto, M Clara; Bernabeu, Ana; Almeida, C Marisa R

    2013-11-15

    Bioremediation potential for buried oil removal, an application still lacking thorough research, was assessed in a specifically designed system in which an artificially contaminated oil layer of sand was buried in a sand column subjected to tidal simulation. The efficiency of biostimulation (BS, fertilizer addition) and bioaugmentation (BA, inoculation of pre-stimulated indigenous hydrocarbon-degrading microorganisms plus fertilizer) compared to natural attenuation was tested during a 180-day experimental period. The effect of BA was evident after 60 days (degradation of hydrocarbons reached 80%). BS efficacy was revealed only after 120 days. Microorganisms and nutrients added at the top of the sand column were able to reach the buried oil layer and contributed to faster oil elimination, an important feature for effective bioremediation treatments. Therefore, autochthonous BA with suitable nutritive conditions results in faster oil-biodegradation, appears to be a cost-effective methodology for buried oil remediation and contributes to the recovery of oil-impacted areas. PMID:24054785

  14. Bioremediation via Methanotrophy: Overview of Recent Findings and Suggestions for Future Research

    PubMed Central

    Semrau, Jeremy D.

    2011-01-01

    Microbially mediated bioremediation of polluted sites has been a subject of much research over the past 30 years, with many different compounds shown to be degraded under both aerobic and anaerobic conditions. Aerobic-mediated bioremediation commonly examines the use of methanotrophs, microorganisms that consume methane as their sole source of carbon and energy. Given the diverse environments in which methanotrophs have been found, the range of substrates they can degrade and the fact that they can be easily stimulated with the provision of methane and oxygen, these microorganisms in particular have been examined for aerobic degradation of chlorinated hydrocarbons. The physiological and phylogenetic diversity of methanotrophy, however, has increased substantially in just the past 5 years. Here in this review, the current state of knowledge of methanotrophy, particularly as it applies to pollutant degradation is summarized, and suggestions for future research provided. PMID:22016748

  15. Environmental Assessment for Selection and Operation of the Proposed Field Research Centers for the Natural and Accelerated Bioremediation Research (NABIR) Program

    SciTech Connect

    N /A

    2000-04-18

    The US Department of Energy (DOE) Office of Biological and Environmental Research (OBER), within the Office of Science (SC), proposes to add a Field Research Center (FRC) component to the existing Natural and Accelerated Bioremediation Research (NABIR) Program. The NABIR Program is a ten-year fundamental research program designed to increase the understanding of fundamental biogeochemical processes that would allow the use of bioremediation approaches for cleaning up DOE's contaminated legacy waste sites. An FRC would be integrated with the existing and future laboratory and field research and would provide a means of examining the fundamental biogeochemical processes that influence bioremediation under controlled small-scale field conditions. The NABIR Program would continue to perform fundamental research that might lead to promising bioremediation technologies that could be demonstrated by other means in the future. For over 50 years, DOE and its predecessor agencies have been responsible for the research, design, and production of nuclear weapons, as well as other energy-related research and development efforts. DOE's weapons production and research activities generated hazardous, mixed, and radioactive waste products. Past disposal practices have led to the contamination of soils, sediments, and groundwater with complex and exotic mixtures of compounds. This contamination and its associated costs and risks represents a major concern to DOE and the public. The high costs, long duration, and technical challenges associated with remediating the subsurface contamination at DOE sites present a significant need for fundamental research in the biological, chemical, and physical sciences that will contribute to new and cost-effective solutions. One possible low-cost approach for remediating the subsurface contamination of DOE sites is through the use of a technology known as bioremediation. Bioremediation has been defined as the use of microorganisms to biodegrade or

  16. Best Practice -- Subsurface Investigations

    SciTech Connect

    Clark Scott

    2010-03-01

    These best practices for Subsurface Survey processes were developed at the Idaho National Laboratory (INL) and later shared and formalized by a sub-committee, under the Electrical Safety Committee of EFCOG. The developed best practice is best characterized as a Tier II (enhanced) survey process for subsurface investigations. A result of this process has been an increase in the safety and lowering of overall cost, when utility hits and their related costs are factored in. The process involves improving the methodology and thoroughness of the survey and reporting processes; or improvement in tool use rather than in the tools themselves. It is hoped that the process described here can be implemented at other sites seeking to improve their Subsurface Investigation results with little upheaval to their existing system.

  17. The Serpentinite Subsurface Microbiome

    NASA Astrophysics Data System (ADS)

    Schrenk, M. O.; Nelson, B. Y.; Brazelton, W. J.

    2011-12-01

    Microbial habitats hosted in ultramafic rocks constitute substantial, globally-distributed portions of the subsurface biosphere, occurring both on the continents and beneath the seafloor. The aqueous alteration of ultramafics, in a process known as serpentinization, creates energy rich, high pH conditions, with low concentrations of inorganic carbon which place fundamental constraints upon microbial metabolism and physiology. Despite their importance, very few studies have attempted to directly access and quantify microbial activities and distributions in the serpentinite subsurface microbiome. We have initiated microbiological studies of subsurface seeps and rocks at three separate continental sites of serpentinization in Newfoundland, Italy, and California and compared these results to previous analyses of the Lost City field, near the Mid-Atlantic Ridge. In all cases, microbial cell densities in seep fluids are extremely low, ranging from approximately 100,000 to less than 1,000 cells per milliliter. Culture-independent analyses of 16S rRNA genes revealed low-diversity microbial communities related to Gram-positive Firmicutes and hydrogen-oxidizing bacteria. Interestingly, unlike Lost City, there has been little evidence for significant archaeal populations in the continental subsurface to date. Culturing studies at the sites yielded numerous alkaliphilic isolates on nutrient-rich agar and putative iron-reducing bacteria in anaerobic incubations, many of which are related to known alkaliphilic and subsurface isolates. Finally, metagenomic data reinforce the culturing results, indicating the presence of genes associated with organotrophy, hydrogen oxidation, and iron reduction in seep fluid samples. Our data provide insight into the lifestyles of serpentinite subsurface microbial populations and targets for future quantitative exploration using both biochemical and geochemical approaches.

  18. Hydrogen as an Indicator to Assess Biological Activity During Trace-Metal Bioremediation

    NASA Astrophysics Data System (ADS)

    Jaffe, P. R.; Komlos, J.; Brown, D. G.; Lovley, D. R.

    2002-05-01

    The design and operation of a trace-metal or radionuclide bioremediation scheme requires that specific redox conditions be achieved at given zones of an aquifer for a predetermined duration. Tools are therefore needed to identify and quantify the terminal electron acceptor processes (TEAPs) that are being achieved during bioremediation in an aquifer, and that this is done at a high spatial resolution. Hydrogen holds the promise of being a key parameter that may be used to identify TEAPs. Theoretical analysis have shown that steady-state hydrogen levels in the subsurface are solely dependent upon the physiological parameters of the hydrogen-consuming microorganisms, and that hydrogen concentrations increase as each successive TEAP yields less energy for bacterial growth. The assumptions for this statement may not hold during a bioremediation scheme in which an organic substrate is injected into the subsurface and where organisms may consume hydrogen and carbon simultaneously. The objective of the research is to gain a basic understanding of the hydrogen dynamics in an aquifer during a trace metal/radionuclide bioremediation scheme. For this purpose, a series of batch studies have been conducted during the first year of this project. In these studies the utilization of acetate and hydrogen by geobacter sulfurreducens were studied. In all cases Fe(III) was the electron acceptor. Microcosms were set up to investigate the utilization of hydrogen and acetate when either of them is the sole electron donor and when both are present and utilized simultaneously as electron donor. These experiments were conducted for varying initial conditions of the hydrogen and acetate concentration, and the disappearance of these compounds plus the evolution of Fe(II) as well as biomass was monitored over time. The results of these studies indicate that the biokinetic coefficients describing the rate of hydrogen utilization are not affected by the simultaneous utilization of acetate. While

  19. Subsurface connection methods for subsurface heaters

    DOEpatents

    Vinegar, Harold J.; Bass, Ronald Marshall; Kim, Dong Sub; Mason, Stanley Leroy; Stegemeier, George Leo; Keltner, Thomas Joseph; Carl, Jr., Frederick Gordon

    2010-12-28

    A system for heating a subsurface formation is described. The system includes a first elongated heater in a first opening in the formation. The first elongated heater includes an exposed metal section in a portion of the first opening. The portion is below a layer of the formation to be heated. The exposed metal section is exposed to the formation. A second elongated heater is in a second opening in the formation. The second opening connects to the first opening at or near the portion of the first opening below the layer to be heated. At least a portion of an exposed metal section of the second elongated heater is electrically coupled to at least a portion of the exposed metal section of the first elongated heater in the portion of the first opening below the layer to be heated.

  20. Bioremediation in Germany: Markets, technologies, and leading companies

    SciTech Connect

    Raphael, T.

    1995-12-31

    Bioremediation has become an internationally accepted remediation tool. Commercial bioremediation activities take place in many European countries, but Germany and the Netherlands are the clear European leaders, with both having a long history of public and private sector activity in biological technologies. The German bioremediation market has been driven by government regulation, in particular the waste laws that apply to contaminated soils. The 1994 German market for bioremediation is estimated at $70 to 100 million (US $). There are at least 150 companies active in bioremediation in Germany, most of which practice bioremediation of hydrocarbon-contaminated soils, either in situ or ex situ. Because of their predominance in the current European market, German firms are well positioned to expand into those nations in the European Union (EU) currently lacking an environmental business infrastructure.

  1. Molecular Tools for Monitoring and Validating Bioremediation

    NASA Astrophysics Data System (ADS)

    Stenuit, Ben; Eyers, Laurent; Schuler, Luc; George, Isabelle; Agathos, Spiros N.

    Bioremediation is now in a position to take advantage of genomic-driven strategies to analyze, monitor and assess its course by considering multiple micro-organisms with various genomes, expressed transcripts and proteins. High-throughput methodologies, including microarrays, fingerprinting, real-time PCR, metagenomics and metaproteomics, show great promise in our environmental interventions against recalcitrant contaminants such as 2,4,6-trinitrotoluene (TNT) that we have been studying for many years. The emerging genomic and metagenomic methodologies will allow us to promote or restore environmental health in impacted sites, monitor remediation activities, identify key microbial players and processes, and finally compile an intelligent database of genes for targeted use in bioremediation.

  2. Natural and accelerated bioremediation research program plan

    SciTech Connect

    1995-09-01

    This draft plan describes a ten-year program to develop the scientific understanding needed to harness and develop natural and enhanced biogeochemical processes to bioremediate contaminated soils, sediments and groundwater at DOE facilities. The Office of Health and Environmental Research (OHER) developed this program plan, with advice and assistance from DOE`s Office of Environmental Management (EM). The program builds on OHER`s tradition of sponsoring fundamental research in the life and environmental sciences and was motivated by OHER`s and Office of Energy Research`s (OER`s) commitment to supporting DOE`s environmental management mission and the belief that bioremediation is an important part of the solution to DOE`s environmental problems.

  3. Bioremediation of petroleum-contaminated soil

    SciTech Connect

    Pearce, K.; Snyman, H.G.; Oellermann, R.A.; Gerber, A.

    1995-12-31

    A pilot-scale study was conducted to evaluate the application of land-farming techniques in bioremediating a soil highly contaminated with petroleum products. A commercial biosupplement, and one prepared with indigenous microorganisms from the contaminated soil, were tested. Application of either of the biosupplements, in addition to the control of pH, moisture, and oxygen levels, resulted in a 94% reduction of the initial total petroleum hydrocarbon concentration (TPHC) (32% mass/mass) over a 70-day period. Implementation of these findings at full scale to bioremediate highly weathered petroleum products showed an average reduction of 89% over 5.5 months. Target levels of 1,400 mg/kg soil were reached from an initial average TPHC concentration of 12,200 mg/kg soil.

  4. Genome-Based Models to Optimize In Situ Bioremediation of Uranium and Harvesting Electrical Energy from Waste Organic Matter

    SciTech Connect

    Lovley, Derek R

    2012-12-28

    The goal of this research was to provide computational tools to predictively model the behavior of two microbial communities of direct relevance to Department of Energy interests: 1) the microbial community responsible for in situ bioremediation of uranium in contaminated subsurface environments; and 2) the microbial community capable of harvesting electricity from waste organic matter and renewable biomass. During this project the concept of microbial electrosynthesis, a novel form of artificial photosynthesis for the direct production of fuels and other organic commodities from carbon dioxide and water was also developed and research was expanded into this area as well.

  5. Mars penetrator: Subsurface science mission

    NASA Technical Reports Server (NTRS)

    Lumpkin, C. K.

    1974-01-01

    A penetrator system to emplace subsurface science on the planet Mars is described. The need for subsurface science is discussed, and the technologies for achieving successful atmospheric entry, Mars penetration, and data retrieval are presented.

  6. Use of molecular techniques in bioremediation.

    PubMed

    Płaza, G; Ulfig, K; Hazen, T C; Brigmon, R L

    2001-01-01

    In a practical sense, biotechnology is concerned with the production of commercial products generated by biological processes. More formally, biotechnology may be defined as "the application of scientific and engineering principles to the processing of material by biological agents to provide goods and services" (Cantor, 2000). From a historical perspective, biotechnology dates back to the time when yeast was first used for beer or wine fermentation, and bacteria were used to make yogurt. In 1972, the birth of recombinant DNA technology moved biotechnology to new heights and led to the establishment of a new industry. Progress in biotechnology has been truly remarkable. Within four years of the discovery of recombinant DNA technology, genetically modified organisms (GMOs) were making human insulin, interferon, and human growth hormone. Now, recombinant DNA technology and its products--GMOs are widely used in environmental biotechnology (Glick and Pasternak, 1988; Cowan, 2000). Bioremediation is one of the most rapidly growing areas of environmental biotechnology. Use of bioremediation for environmental clean up is popular due to low costs and its public acceptability. Indeed, bioremediation stands to benefit greatly and advance even more rapidly with the adoption of molecular techniques developed originally for other areas of biotechnology. The 1990s was the decade of molecular microbial ecology (time of using molecular techniques in environmental biotechnology). Adoption of these molecular techniques made scientists realize that microbial populations in the natural environments are much more diverse than previously thought using traditional culture methods. Using molecular ecological methods, such as direct DNA isolation from environmental samples, denaturing gradient gel electrophoresis (DGGE), PCR methods, nucleic acid hybridization etc., we can now study microbial consortia relevant to pollutant degradation in the environment. These techniques promise to

  7. Intrinsic bioremediation modeling to support Superfund site closure

    SciTech Connect

    Bedard, A.H.; Day, M.J.; Johnson, R.H.; Ritter, K.J.; Stancel, S.G.; Thomson, J.A.M.

    1997-09-01

    Closure of the groundwater component of a major Superfund site has been accomplished by a combination of source control, engineered in-situ bioremediation, and subsequent long-term intrinsic bioremediation. Engineered bioremediation outside the source control area resulted in very significant contaminant mass removal. This allowed intrinsic bioremediation to be considered as a passive remedial management method of achieving cleanup objectives after active remediation needed. Modeling demonstrated that intrinsic bioremediation would achieve cleanup objectives (for this site, Federal drinking water standards) within ten years of shutdown of the active bioremediation system. Modeling showed that residual electron acceptors and nutrients distributed in the aquifer during engineered bioremediation greatly enhance the intrinsic bioremediation process. The results of the modeling effort led to the active system being shut down a year ahead of schedule, allowing the project to move into a low-maintenance intrinsic bioremediation and long-term monitoring phase. The modeling demonstration coupled Visual MODFLOW{copyright} and BioTrans{copyright} to simulate groundwater flow, solute transport, and oxygen-limited, multi-species biodegradation. Regional flow evaluation, detailed model sensitivity analyses, and subarea modeling were employed to provide support to model predictions. Predictions will be tested by subsequent progress and compliance monitoring. Site closure began in early 1996.

  8. Bioremediation Education Science and Technology (BEST) Program Annual Report 1999

    SciTech Connect

    Hazen, Terry C.

    2000-07-01

    The Bioremediation, Education, Science and Technology (BEST) partnership provides a sustainable and contemporary approach to developing new bioremedial technologies for US Department of Defense (DoD) priority contaminants while increasing the representation of underrepresented minorities and women in an exciting new biotechnical field. This comprehensive and innovative bioremediation education program provides under-represented groups with a cross-disciplinary bioremediation cirruculum and financial support, coupled with relevant training experiences at advanced research laboratories and field sites. These programs are designed to provide a stream of highly trained minority and women professionals to meet national environmental needs.

  9. Elevated nitrate enriches microbial functional genes for potential bioremediation of complexly contaminated sediments

    PubMed Central

    Xu, Meiying; Zhang, Qin; Xia, Chunyu; Zhong, Yuming; Sun, Guoping; Guo, Jun; Yuan, Tong; Zhou, Jizhong; He, Zhili

    2014-01-01

    Nitrate is an important nutrient and electron acceptor for microorganisms, having a key role in nitrogen (N) cycling and electron transfer in anoxic sediments. High-nitrate inputs into sediments could have a significant effect on N cycling and its associated microbial processes. However, few studies have been focused on the effect of nitrate addition on the functional diversity, composition, structure and dynamics of sediment microbial communities in contaminated aquatic ecosystems with persistent organic pollutants (POPs). Here we analyzed sediment microbial communities from a field-scale in situ bioremediation site, a creek in Pearl River Delta containing a variety of contaminants including polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons (PAHs), before and after nitrate injection using a comprehensive functional gene array (GeoChip 4.0). Our results showed that the sediment microbial community functional composition and structure were markedly altered, and that functional genes involved in N-, carbon (C)-, sulfur (S)-and phosphorus (P)- cycling processes were highly enriched after nitrate injection, especially those microorganisms with diverse metabolic capabilities, leading to potential in situ bioremediation of the contaminated sediment, such as PBDE and PAH reduction/degradation. This study provides new insights into our understanding of sediment microbial community responses to nitrate addition, suggesting that indigenous microorganisms could be successfully stimulated for in situ bioremediation of POPs in contaminated sediments with nitrate addition. PMID:24671084

  10. Using sediment microbial fuel cells (SMFCs) for bioremediation of polycyclic aromatic hydrocarbons (PAHs).

    PubMed

    Sherafatmand, Mohammad; Ng, How Yong

    2015-11-01

    In this study, a sediment microbial fuel cell (SMFC) was explored to bioremediate polycyclic aromatic hydrocarbons (PAHs) in water originated from soil. The results showed consistent power generations of 6.02±0.34 and 3.63±0.37 mW/m(2) under an external resistance of 1500 Ω by the aerobic and anaerobic SMFC, respectively. Although the power generations were low, they had relatively low internal resistances (i.e., 436.6±69.4 and 522.1±1.8 Ω for the aerobic and anaerobic SMFC, respectively) in comparison with the literature. Nevertheless, the significant benefit of this system was its bioremediation capabilities, achieving 41.7%, 31.4% and 36.2% removal of naphthalene, acenaphthene and phenanthrene, respectively, in the aerobic environment and 76.9%, 52.5% and 36.8%, respectively, in the anaerobic environment. These results demonstrated the ability of SMFCs in stimulating microorganisms for bioremediation of complex and recalcitrant PAHs. PMID:26081161

  11. Bioremediation of petroleum pollutants: Diversity and environmental aspects of hydrocarbon biodegradation

    SciTech Connect

    Atlas, R.M.; Cerniglia, C.E.

    1995-05-01

    The manufacture, transportation, and distribution of petroleum and chemical products during the last century has resulted in hydrocarbon-contamination becoming a major environmental problem. Most of the environmental inputs of petroleum are accommodated largely due to the capacities of microorganisms to biodegrade hydrocarbons. Bioremediation has gained significant political support among competing technologies for in situ cleanup of pollutants. In addition to its potential for local cleanup of contaminated water and soil, bioremediation may have a future role in solving problems on a global scale, including removal of greenhouse gases from the atmosphere. This article examines in detail the following topics: bacterial and fungal metabolism of hydrocarbons; bioremediation of marine oil spills; site remediation; performance and regulatory oversight. In summary diverse microorganisms using diverse metabolic pathways have the capacities for degrading a wide spectrum of hydrocarbon structures in petroleum. Some pathways lead to detoxification and destruction of the pollutants whereas others activate potentially harmful compounds. In most cases of detoxification, environmental modification is used to stimulate the biodegradative activities of indigenous organisms. Biodegradation is emerging as an important cost-effective treatment for marine oil spills and contaminated sites. 13 refs., 2 figs.

  12. Pilot-scale feasibility of petroleum hydrocarbon-contaminated soil in situ bioremediation

    SciTech Connect

    Walker, J.F. Jr.; Walker, A.B.

    1995-12-31

    An environmental project was conducted to evaluate in situ bioremediation of petroleum hydrocarbon-contaminated soils on Kwajalein Island, a US Army Kwajalein Atoll base in the Republic of the Marshall Islands. Results of laboratory column studies determined that nutrient loadings stimulated biodegradation rates and that bioremediation of hydrocarbon-contaminated soils at Kwajalein was possible using indigenous microbes. The column studies were followed by an {approximately}10-month on-site demonstration at Kwajalein to further evaluate in situ bioremediation and to determine design and operating conditions necessary to optimize the process. The demonstration site contained low levels of total petroleum hydrocarbons (diesel fuel) in the soil near the ground surface, with concentrations increasing to {approximately}10,000 mg/kg in the soil near the groundwater. The demonstration utilized 12 in situ plots to evaluate the effects of various combinations of water, air, and nutrient additions on both the microbial population and the hydrocarbon concentration within the treatment plots as a function of depth from the ground surface.

  13. Uranium Biomineralization By Natural Microbial Phosphatase Activities in the Subsurface

    SciTech Connect

    Taillefert, Martial

    2015-04-01

    This project investigated the geochemical and microbial processes associated with the biomineralization of radionuclides in subsurface soils. During this study, it was determined that microbial communities from the Oak Ridge Field Research subsurface are able to express phosphatase activities that hydrolyze exogenous organophosphate compounds and result in the non-reductive bioimmobilization of U(VI) phosphate minerals in both aerobic and anaerobic conditions. The changes of the microbial community structure associated with the biomineralization of U(VI) was determined to identify the main organisms involved in the biomineralization process, and the complete genome of two isolates was sequenced. In addition, it was determined that both phytate, the main source of natural organophosphate compounds in natural environments, and polyphosphate accumulated in cells could also be hydrolyzed by native microbial population to liberate enough orthophosphate and precipitate uranium phosphate minerals. Finally, the minerals produced during this process are stable in low pH conditions or environments where the production of dissolved inorganic carbon is moderate. These findings suggest that the biomineralization of U(VI) phosphate minerals is an attractive bioremediation strategy to uranium bioreduction in low pH uranium-contaminated environments. These efforts support the goals of the SBR long-term performance measure by providing key information on "biological processes influencing the form and mobility of DOE contaminants in the subsurface".

  14. Evaluating the efficacy of bioremediating a diesel-contaminated soil using ecotoxicological and bacterial community indices.

    PubMed

    Khudur, Leadin Salah; Shahsavari, Esmaeil; Miranda, Ana F; Morrison, Paul D; Nugegoda, Dayanthi; Ball, Andrew S

    2015-10-01

    Diesel represents a common environmental contaminant as a result of operation, storage, and transportation accidents. The bioremediation of diesel in a contaminated soil is seen as an environmentally safe approach to treat contaminated land. The effectiveness of the remediation process is usually assessed by the degradation of the total petroleum hydrocarbon (TPH) concentration, without considering ecotoxicological effects. The aim of this study was to assess the efficacy of two bioremediation strategies in terms of reduction in TPH concentration together with ecotoxicity indices and changes in the bacterial diversity assessed using PCR-denaturing gradient gel electrophoresis (DGGE). The biostimulation strategy resulted in a 90 % reduction in the TPH concentration versus 78 % reduction from the natural attenuation strategy over 12 weeks incubation in a laboratory mesocosm-containing diesel-contaminated soil. In contrast, the reduction in the ecotoxicity resulting from the natural attenuation treatment using the Microtox and earthworm toxicity assays was more than double the reduction resulting from the biostimulation treatment (45 and 20 % reduction, respectively). The biostimulated treatment involved the addition of nitrogen and phosphorus in order to stimulate the microorganisms by creating an optimal C:N:P molar ratio. An increased concentration of ammonium and phosphate was detected in the biostimulated soil compared with the naturally attenuated samples before and after the remediation process. Furthermore, through PCR-DGGE, significant changes in the bacterial community were observed as a consequence of adding the nutrients together with the diesel (biostimulation), resulting in the formation of distinctly different bacterial communities in the soil subjected to the two strategies used in this study. These findings indicate the suitability of both bioremediation approaches in treating hydrocarbon-contaminated soil, particularly biostimulation. Although

  15. Influence of Reactive Transport on the Reduction of U(VI) in the Presence of Fe(III) and Nitrate: Implications for U(VI) Immobilization by Bioremediation / Biobarriers- Final Report

    SciTech Connect

    B.D. Wood

    2007-01-01

    Subsurface contamination by metals and radionuclides represent some of the most challenging remediation problems confronting the Department of Energy (DOE) complex. In situ remediation of these contaminants by dissimilatory metal reducing bacteria (DMRB) has been proposed as a potential cost effective remediation strategy. The primary focus of this research is to determine the mechanisms by which the fluxes of electron acceptors, electron donors, and other species can be controlled to maximize the transfer of reductive equivalents to the aqueous and solid phases. The proposed research is unique in the NABIR portfolio in that it focuses on (i) the role of flow and transport in the initiation of biostimulation and the successful sequestration of metals and radionuclides [specifically U(VI)], (ii) the subsequent reductive capacity and stability of the reduced sediments produced by the biostimulation process, and (iii) the potential for altering the growth of biomass in the subsurface by the addition of specific metabolic uncoupling compounds. A scientifically-based understanding of these phenomena are critical to the ability to design successful bioremediation schemes. The laboratory research will employ Shewanella putrefaciens (CN32), a facultative DMRB that can use Fe(III) oxides as a terminal electron acceptor. Sediment-packed columns will be inoculated with this organism, and the reduction of U(VI) by the DMRB will be stimulated by the addition of a carbon and energy source in the presence of Fe(III). Separate column experiments will be conducted to independently examine: (1) the importance of the abiotic reduction of U(VI) by biogenic Fe(II); (2) the influence of the transport process on Fe(III) reduction and U(VI) immobilization, with emphasis on methods for controlling the fluxes of aqueous species to maximize uranium reduction; (3) the reductive capacity of biologically-reduced sediments (with respect to re-oxidation by convective fluxes of O2 and NO3-) and

  16. ASSESSMENT OF THE SUBSURFACE FATE OF MONOETHANOLAMINE

    SciTech Connect

    James A. Sorensen; John R. Gallagher; Lori G. Kays

    2000-05-01

    Burial of amine reclaimer unit sludges and system filters has resulted in contamination of soil at the CanOxy Okotoks decommissioned sour gas-processing plant with amines, amine byproducts, and salts. A three-phase research program was devised to investigate the natural attenuation process that controls the subsurface transport and fate of these contaminants and to apply the results toward the development of a strategy for the remediation of this type of contamination in soils. Phase I experimental activities examined interactions between monoethanolamine (MEA) and sediment, the biodegradability of MEA in soils at various concentrations and temperatures, and the biodegradability of MEA sludge contamination in a soil slurry bioreactor. The transport and fate of MEA in the subsurface was found to be highly dependant on the nature of the release, particularly MEA concentration and conditions of the subsurface environment, i.e., pH, temperature, and oxygen availability. Pure compound biodegradation experiments in soil demonstrated rapid biodegradation of MEA under aerobic conditions and moderate temperatures (>6 C). Phase II landfarming activities confirmed that these contaminants are readily biodegradable in soil under ideal laboratory conditions, yet considerable toxicity was observed in the remaining material. Examination of water extracts from the treated soil suggested that the toxicity is water-soluble. Phase II activities led to the conclusion that landfarming is not the most desirable bioremediation technique; however, an engineered biopile with a leachate collection system could remove the remaining toxic fraction from the soil. Phase III was initiated to conduct field-based experimental activities to examine the optimized remediation technology. A pilot-scale engineered biopile was constructed at a decommissioned gas-sweetening facility in Okotoks, Alberta, Canada. On the basis of a review of the analytical and performance data generated from soil and

  17. A scrutiny of heterogeneity at the TCE Source Area BioREmediation (SABRE) test site

    NASA Astrophysics Data System (ADS)

    Rivett, M.; Wealthall, G. P.; Mcmillan, L. A.; Zeeb, P.

    2015-12-01

    A scrutiny of heterogeneity at the UK's Source Area BioREmediation (SABRE) test site is presented to better understand how spatial heterogeneity in subsurface properties and process occurrence may constrain performance of enhanced in-situ bioremediation (EISB). The industrial site contained a 25 to 45 year old trichloroethene (TCE) dense non-aqueous phase liquid (DNAPL) that was exceptionally well monitored via a network of multilevel samplers and high resolution core sampling. Moreover, monitoring was conducted within a 3-sided sheet-pile cell that allowed a controlled streamtube of flow to be drawn through the source zone by an extraction well. We primarily focus on the longitudinal transect of monitoring along the length of the cell that provides a 200 groundwater point sample slice along the streamtube of flow through the DNAPL source zone. TCE dechlorination is shown to be significant throughout the cell domain, but spatially heterogeneous in occurrence and progress of dechlorination to lesser chlorinated ethenes - it is this heterogeneity in dechlorination that we primarily scrutinise. We illustrate the diagnostic use of the relative occurrence of TCE parent and daughter compounds to confirm: dechlorination in close proximity to DNAPL and enhanced during the bioremediation; persistent layers of DNAPL into which gradients of dechlorination products are evident; fast flowpaths through the source zone where dechlorination is less evident; and, the importance of underpinning flow regime understanding on EISB performance. Still, even with such spatial detail, there remains uncertainty over the dataset interpretation. These includes poor closure of mass balance along the cell length for the multilevel sampler based monitoring and points to needs to still understand lateral flows (even in the constrained cell), even greater spatial resolution of point monitoring and potentially, not easily proven, ethene degradation loss.

  18. Unsaturated and saturated zone bioremediation at the Sparks solvent/fuel site

    SciTech Connect

    Buchanan, L.; Eisenbeis, J.; Smith, M.; Kilkenny, S.

    1997-12-31

    Activities to remediate petroleum-contaminated subsurface and groundwater at the Sparks Solvent/Fuel Site (SSFS), a major petroleum distribution facility in Sparks, Nevada have included operation of an active soil vapor extraction (SVE) and groundwater extraction/treatment system; a full site evaluation of intrinsic bioremediation in groundwater through injection of treated, oxygenated groundwater. The active remediation system has removed approximately 2.8 million pounds of hydrocarbons from soils and groundwater since system startup in November 1995, of which 2.3 million pounds are estimated to be due to SVE-enhanced biodegradation. An intrinsic bioremediation evaluation was performed to estimate contaminant mass removal due to intrinsic biological processes in groundwater and to obtain information on biological systems present at the site. Areas of nitrate reduction, iron reduction, sulfate reduction, and methanogenesis were identified in the affected aquifer. In addition, complete anaerobic dechlorination of tetrachlorethene/trichloroethene (PCE/TCE) was documented by the presence of vinyl chloride (VC) and ethene. Biodegradation rates, estimated using the Buscheck and Alcantar (1995) method, and site data were incorporated in a site contaminant transport model, results of which showed that approximately 50 pounds of benzene are removed per year by intrinsic processes. A small-scale system is currently being operated to test implementation of an enhanced in situ bioremediation system via injection of treated/oxygenated groundwater. Test data show that injection introduces water to 12 feet below the water table, biotic and/or abiotic oxygen demands have prevented oxygen breakthrough at wells 10 feet from the trench after more than three months of operation, and nitrate consumption via biological processes and significant soil flushing of organic contaminants occurs.

  19. Subsurface contaminants focus area

    SciTech Connect

    1996-08-01

    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.

  20. Applications of subsurface microscopy.

    PubMed

    Tetard, Laurene; Passian, Ali; Farahi, Rubye H; Voy, Brynn H; Thundat, Thomas

    2012-01-01

    Exploring the interior of a cell is of tremendous importance in order to assess the effects of nanomaterials on biological systems. Outside of a controlled laboratory environment, nanomaterials will most likely not be conveniently labeled or tagged so that their translocation within a biological system cannot be easily identified and quantified. Ideally, the characterization of nanomaterials within a cell requires a nondestructive, label-free, and subsurface approach. Subsurface nanoscale imaging represents a real challenge for instrumentation. Indeed the tools available for high resolution characterization, including optical, electron or scanning probe microscopies, mainly provide topography images or require taggants that fluoresce. Although the intercellular environment holds a great deal of information, subsurface visualization remains a poorly explored area. Recently, it was discovered that by mechanically perturbing a sample, it was possible to observe its response in time with nanoscale resolution by probing the surface with a micro-resonator such as a microcantilever probe. Microcantilevers are used as the force-sensing probes in atomic force microscopy (AFM), where the nanometer-scale probe tip on the microcantilever interacts with the sample in a highly controlled manner to produce high-resolution raster-scanned information of the sample surface. Taking advantage of the existing capabilities of AFM, we present a novel technique, mode synthesizing atomic force microscopy (MSAFM), which has the ability to probe subsurface structures such as non-labeled nanoparticles embedded in a cell. In MSAFM mechanical actuators (PZTs) excite the probe and the sample at different frequencies as depicted in the first figure of this chapter. The nonlinear nature of the tip-sample interaction, at the point of contact of the probe and the surface of the sample, in the contact mode AFM configuration permits the mixing of the elastic waves. The new dynamic system comprises new

  1. A Reactive Transport Simulator for Biogeochemical Processes in Subsurface System

    Energy Science and Technology Software Center (ESTSC)

    2003-04-01

    BIOGEOCHEM is a Fortran code that mumerically simulates the coupled processes of solute transport, microbial population dynamics, microbial metabolism, and geochemical reactions. The potential applications of the code include, but not limited to, (a) sensitivity and uncertainty analyses for assessing the impact of microbial activity on subsurface geochemical systems; (b) extraction of biogeochemical parameter values from field observations or laboratory measurements, (c) helping to design and optimize laboratory biogeochemical experiments, and (d) data integration. Methodmore » of Solution: A finite difference method and a Newton-Raphson technique are used to solve a set of coupled nonlinear partial differential equations and algebraic equations. Practical Application: Environmental analysis, bioremediation performance assessments of radioactive or non-radioactive wase disposal, and academic research.« less

  2. In situ bioremediation for the Hanford carbon tetrachloride plume. Innovative technology summary report

    SciTech Connect

    Not Available

    1999-04-01

    The 200 Area at Hanford (also called the Central Plateau) contains approximately 817 waste sites, 44 facilities to be demolished, and billions of gallons of contaminated groundwater resulting from chemical processing plants and associated waste facilities (e.g., waste tanks). From 1955 to 1973, carbon tetrachloride, nitrate, and other materials were discharged to subsurface liquid waste disposal facilities in the 200 Area. As much as 600,000 kilograms of carbon tetrachloride may have entered the soil column and a portion of this has contaminated the underlying aquifer. In Situ Bioremediation for the Hanford Carbon Tetrachloride Plume (ISB), which is the term used in this report for an in situ treatment process using indigenous micro-organisms with a computer based Accelerated Bioremediation Design Tool (ABDT), remediates groundwater contaminated with volatile organic compounds (VOCs) and nitrates under anaerobic conditions. ISB involves the injection of nutrients into the groundwater and subsequent extraction and re-injection of the groundwater to provide nutrient distribution in the aquifer.

  3. Fiber optic affinity ligand sensor for quantification of petroleum and bioremediation

    NASA Astrophysics Data System (ADS)

    Wavering, Thomas A.; Elster, Jennifer L.; Luo, Shufang; Evans, Mishell K.; Pennington, Charles; Van Tassell, Roger; Jones, Mark E.

    2001-02-01

    A novel system incorporating optical fiber long-period grating (LPG)-based sensors for rapid detection of biological targets is presented to address the current need for highly responsive, inexpensive, instrumentation for in-situ subsurface bioremediation technologies. With the appropriate configuration, the LPG sensor is able to measure key environmental parameters. The sensor allows for highly sensitive, real-time, refractive index measurements and by applying affinity coatings to the fiber surface, specific binding of molecules can be accomplished using swellable polymers or ligand-based affinity coatings. Advantages of the sensors have are that they are highly responsive, low profile, and can be serially multiplexed within a single-ended probe-like arrangement. This arrangement can be utilized either locally for site characterization or as a distributed sensor to map contaminant levels at multiple depths over a large area. The performance advantages make optical fiber sensors ideal for detection of environmental targets in drinking water, groundwater, soil, and other complex samples. This paper presents recent long-period grating-based sensor results that demonstrate the potential for bioremediation as well as a variety of other chemical and biological sensing applications.

  4. Multicomponent reactive transport modeling of uranium bioremediation field experiments

    SciTech Connect

    Fang, Yilin; Yabusaki, Steven B.; Morrison, Stan J.; Amonette, James E.; Long, Philip E.

    2009-10-15

    Biostimulation field experiments with acetate amendment are being performed at a former uranium mill tailings site in Rifle, Colorado, to investigate subsurface processes controlling in situ bioremediation of uranium-contaminated groundwater. An important part of the research is identifying and quantifying field-scale models of the principal terminal electron-accepting processes (TEAPs) during biostimulation and the consequent biogeochemical impacts to the subsurface receiving environment. Integrating abiotic chemistry with the microbially mediated TEAPs in the reaction network brings into play geochemical observations (e.g., pH, alkalinity, redox potential, major ions, and secondary minerals) that the reactive transport model must recognize. These additional constraints provide for a more systematic and mechanistic interpretation of the field behaviors during biostimulation. The reaction network specification developed for the 2002 biostimulation field experiment was successfully applied without additional calibration to the 2003 and 2007 field experiments. The robustness of the model specification is significant in that 1) the 2003 biostimulation field experiment was performed with 3 times higher acetate concentrations than the previous biostimulation in the same field plot (i.e., the 2002 experiment), and 2) the 2007 field experiment was performed in a new unperturbed plot on the same site. The biogeochemical reactive transport simulations accounted for four TEAPs, two distinct functional microbial populations, two pools of bioavailable Fe(III) minerals (iron oxides and phyllosilicate iron), uranium aqueous and surface complexation, mineral precipitation, and dissolution. The conceptual model for bioavailable iron reflects recent laboratory studies with sediments from the Old Rifle Uranium Mill Tailings Remedial Action (UMTRA) site that demonstrated that the bulk (~90%) of Fe(III) bioreduction is associated with the phyllosilicates rather than the iron oxides

  5. BIOREMEDIATION FIELD EVALUATION - HILL AIR FORCE BASE, UTAH

    EPA Science Inventory

    In 1990, the U.S. Environmental Protection Agency (EPA) established the Bioremediation Field Initiative as part of its overall strategy to increase the use of bioremediation to treat hazardous wastes at Comprehensive Environmental Response, Compensation, and Liabil- ity Act (C...

  6. MUTAGENICITY OF PAH-CONTAMINATED SOILS DURING BIOREMEDIATION

    EPA Science Inventory

    Bioremediation of contaminated soils is considered an effective method for reducing potential health hazards. Although it is assumed that (bio)remediation is a detoxifying process, degradation products of compounds such as polycyclic aromatic compounds (PACs) can be more toxic th...

  7. In situ and on-site bioremediation. Volume 2

    SciTech Connect

    Alleman, B.C.; Leeson, A.

    1997-11-01

    Collected in Volume 2 are articles on the bioremediation of media contaminated by polycyclic aromatic hydrocarbons (PAHs), PCBs and chlorinated aromatics, explosives and nitroaromatics, pesticides and herbicides, and other recalcitrant compounds. The technologies discussed include intrinsic remediation/natural attenuation, fungal technologies, application of surfactants, composting, and landfarming. This volume also contains articles on field methods and process monitoring to support bioremediation applications.

  8. 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...

  9. Bioremediation: A natural solution. [Decontamination of soils and groundwater

    SciTech Connect

    Hicks, B.N.; Caplan, J.A. )

    1993-01-15

    Bioremediation is an attractive remediation alternative because most full-scale bioremediation projects involve cost-effective contaminant treatment on-site. Recently, large scale bioremediation projects have included cleanups of ocean tanker spills, land-based chemical spills, and leaking chemical and petroleum storage tanks. Contaminated matrices have included beaches, soils, groundwater, surface waters (i.e., pits, ponds, lagoons), process waste streams and grease traps. Bioremediation is especially cost-effective when both soil and groundwater matrices are impacted because one remediation treatment system can be design to treat both media simultaneously in place. The primary advantages of in situ bioremediation include: on-site destruction of contaminants; accelerated cleanup time; minimal disruption to operations; lower remediation costs; and reduction of future liability.

  10. Combination of aquifer thermal energy storage and enhanced bioremediation: resilience of reductive dechlorination to redox changes.

    PubMed

    Ni, Zhuobiao; van Gaans, Pauline; Smit, Martijn; Rijnaarts, Huub; Grotenhuis, Tim

    2016-04-01

    To meet the demand for sustainable energy, aquifer thermal energy storage (ATES) is widely used in the subsurface in urban areas. However, contamination of groundwater, especially with chlorinated volatile organic compounds (CVOCs), is often being encountered. This is commonly seen as an impediment to ATES implementation, although more recently, combining ATES and enhanced bioremediation of CVOCs has been proposed. Issues to be addressed are the high water flow velocities and potential periodic redox fluctuation that accompany ATES. A column study was performed, at a high water flow velocity of 2 m/h, simulating possible changes in subsurface redox conditions due to ATES operation by serial additions of lactate and nitrate. The impacts of redox changes on reductive dechlorination as well as the microbial response of Dehalococcoides (DHC) were evaluated. The results showed that, upon lactate addition, reductive dechlorination proceeded well and complete dechlorination from cis-DCE to ethene was achieved. Upon subsequent nitrate addition, reductive dechlorination immediately ceased. Disruption of microorganisms' retention was also immediate and possibly detached DHC which preferred attaching to the soil matrix under biostimulation conditions. Initially, recovery of dechlorination was possible but required bioaugmentation and nutrient amendment in addition to lactate dosing. Repeated interruption of dechlorination and DHC activity by nitrate dosing appeared to be less easily reversible requiring more efforts for regenerating dechlorination. Overall, our results indicate that the microbial resilience of DHC in biosimulated ATES conditions is sensitive to redox fluctuations. Hence, combining ATES with bioremediation requires dedicated operation and monitoring on the aquifer geochemical conditions. PMID:26711280

  11. The genome of Geobacter bemidjiensis, exemplar for the subsurface clade of Geobacter species that predominate in Fe(III)-reducing subsurface environments

    SciTech Connect

    Aklujkar, Muktak; Young, Nelson D; Holmes, Dawn; Chavan, Milind; Risso, Carla; Kiss, Hajnalka; Han, Cliff; Land, Miriam L; Lovley, Derek

    2010-01-01

    Background. Geobacter species in a phylogenetic cluster known as subsurface clade 1 are often the predominant microorganisms in subsurface environments in which Fe(III) reduction is the primary electron-accepting process. Geobacter bemidjiensis, a member of this clade, was isolated from hydrocarbon-contaminated subsurface sediments in Bemidji, Minnesota, and is closely related to Geobacter species found to be abundant at other subsurface sites. This study examines whether there are significant differences in the metabolism and physiology of G. bemidjiensis compared to non-subsurface Geobacter species. Results. Annotation of the genome sequence of G. bemidjiensis indicates several differences in metabolism compared to previously sequenced non-subsurface Geobacteraceae, which will be useful for in silico metabolic modeling of subsurface bioremediation processes involving Geobacter species. Pathways can now be predicted for the use of various carbon sources such as propionate by G. bemidjiensis. Additional metabolic capabilities such as carbon dioxide fixation and growth on glucose were predicted from the genome annotation. The presence of different dicarboxylic acid transporters and two oxaloacetate decarboxylases in G. bemidjiensis may explain its ability to grow by disproportionation of fumarate. Although benzoate is the only aromatic compound that G. bemidjiensis is known or predicted to utilize as an electron donor and carbon source, the genome suggests that this species may be able to detoxify other aromatic pollutants without degrading them. Furthermore, G. bemidjiensis is auxotrophic for 4-aminobenzoate, which makes it the first Geobacter species identified as having a vitamin requirement. Several features of the genome indicated that G. bemidjiensis has enhanced abilities to respire, detoxify and avoid oxygen. Conclusion. Overall, the genome sequence of G. bemidjiensis offers surprising insights into the metabolism and physiology of Geobacteraceae in

  12. In situ recycling of contaminated soil uses bioremediation

    SciTech Connect

    Shevlin, P.J.; Reel, D.A.

    1996-04-01

    OxyChem Pipeline Operations, primarily an ethylene and propylene products mover, has determined that substantial savings can be realized by adopting a bioremediation maintenance and recycling approach to hydrocarbon-contaminated soil. By this method, the soil can be recycled in situ, or in containers. To implement the soil-recycling program, OxyChem elected to use a soil remediator and natural absorbent product, Oil Snapper. This field maintenance material, based on an Enhanced Urea Technology, provides a diet to stimulate the growth of hydrocarbon-eating microbes. It works well either with indigenous soil microbes or with commercial microbes. The product is carried in field vehicles, which makes it immediately available when leaks or spills are discovered. Procedure for clean-up is to apply product and mix it into affected soil. Thus the contaminant is contained, preventing further migration; the contaminant is dispersed throughout the product, making it more accessible to the microbes; nutrients are immediately available to the microbes; and the material contributes aeration and moisture-retention properties.

  13. Attenuation of chromium toxicity by bioremediation technology.

    PubMed

    Mohanty, Monalisa; Patra, Hemanta Kumar

    2011-01-01

    Chromium is an important toxic environmental pollutant. Chromium pollution results largely from industrial activities, but other natural and anthropogenic sources also contribute to the problem. Plants that are exposed to environmental contamination by chromium are affected in diverse ways, including a tendency to suffer metabolic stress. The stress imposed by Cr exposure also extends to oxidative metabolic stress in plants that leads to the generation of active toxic oxygen free radicals. Such active free radicals degrade essential biomolecules and distort plant biological membranes. In this chapter, we describe sources of environmental chromium contamination, and provide information about the toxic impact of chromium on plant growth and metabolism. In addition, we address different phytoremediation processes that are being studied for use worldwide, in contaminated regions, to address and mitigate Cr pollution. There has been a long history of attempts to successfully mitigate the toxic effects of chromium-contaminated soil on plants and other organisms. One common approach, the shifting of polluted soil to landfills, is expensive and imposes environmental risks and health hazards of its own. Therefore, alternative eco-friendly bioremediation approaches are much in demand for cleaning chromium-polluted areas. To achieve its cleaning effects, bioremediation utilizes living organisms (bacteria, algae, fungi, and plants) that are capable of absorbing and processing chromium residues in ways which amend or eliminate it. Phytoremediation (bioremediation with plants) techniques are increasingly being used to reduce heavy metal contamination and to minimize the hazards of heavy metal toxicity. To achieve this, several processes, viz., rhizofiltration, phytoextraction, phytodetoxification, phytostabilization, and phytovolatilization, have been developed and are showing utility in practice, or promise. Sources of new native hyperaccumulator plants for use at contaminated

  14. Bioremediation of nitroaromatic and haloaromatic compounds

    SciTech Connect

    Alleman, B.C.; Leeson, A.

    1999-10-01

    Sites contaminated with explosive compounds, pesticides, herbicides, PCBs, and other aromatic compounds present formidable technical, regulatory, and financial challenges. The application of bioremediation technologies at such sites offers the promise of cost-effective site remediation that can serve as a key component of a well-formulated strategy for achieving site closure. This volume presents the results of bench-, pilot-, and field-scale projects focused on the use of biological approaches to remediate problem compounds, such as RDX, HMX, TNT, DDT, 2,4-D, nitro- and chlorobenzenes, nitroaniline, chloroaniline, hexachlorobenzene, PCPs, PCBs, and dichlorophenol in soils and groundwater.

  15. Bioremediation of uranium contaminated Fernald soils

    SciTech Connect

    Delwiche, M.E.; Wey, J.E.; Torma, A.E.

    1994-12-31

    This study investigated the use of microbial bioleaching for removal of uranium from contaminated soils. The ability of bacteria to assist in oxidation and solubilization of uranium was compared to the ability of fungi to produce complexing compounds which have the same effect. Biosorption of uranium by fungi was also measured. Soil samples were examined for changes in mineralogical properties due to these processes. On the basis of these laboratory scale studies a generalized flow sheet is proposed for bioremediation of contaminated Fernald soils.

  16. Monitoring plant bioremediation of volatile organic compounds (VOCs) using open path Fourier transform infrared (FT-IR) spectrometry

    SciTech Connect

    Hoffman, R.M.; Visser, V.P.; Davis, L.C.; Erickson, L.E.; Muralidharan, N.; Hammaker, R.M.; Fateley, W.G.

    1994-12-31

    This study addresses a viable and natural solution to the elimination of volatile organic compounds (VOCs), which are pollutants, through the bioremediation process. Plants and associated rhizosphere bacteria have the ability to bioremediate both volatile and non-volatile organic compounds. For volatile compounds, intersystem transfer by transpiration may be a matter for concern when plants interact with such materials. The authors have monitored, using FT-IR, the potential transfer from subsurface water in the presence of toluene-adapted alfalfa plants. These experiments show that the plants and/or their associated micro-organisms effectively degrade toluene so that potential intersystem transfer of VOCs by transpiration may be quite manageable with adapted plants. Presently, the authors are monitoring 1,1,1-trichloroethane (TCA), chloroform (CHCl{sub 3}), and, trichloroethylene (TCE) from the subsurface water and the gas phase above the plants. TCA does not show an indication of degradation, whereas TCE does. Methane is produced in the groundwater but not transferred to the atmosphere, indicating the presence of a consortium of methanogens and methanotrophs in this soil. The TCE presumably is the substrate for methane production based on chloride ion accumulation. The majority of the TCE must be degraded aerobically to yield CO{sub 2} in the vadose zone. The FT-IR spectrometer can quickly determine and analyze contaminants in the gas phase, groundwater and plant tissue.

  17. Bioremediation of polluted soil through the combined application of plants, earthworms and organic matter.

    PubMed

    Macci, Cristina; Doni, Serena; Peruzzi, Eleonora; Ceccanti, Brunello; Masciandaro, Grazia

    2012-10-26

    Two plant species (Paulownia tomentosa and Cytisus scoparius), earthworms (Eisenia fetida), and organic matter (horse manure) were used as an ecological approach to bioremediate a soil historically contaminated by heavy metals and hydrocarbons. The experiment was carried out for six months at a mesoscale level using pots containing 90 kg of polluted soil. Three different treatments were performed for each plant: (i) untreated planted soil as a control (C); (ii) planted soil + horse manure (20:1 w/w) (M); (iii) planted soil + horse manure + 15 earthworms (ME). Both the plant species were able to grow in the polluted soil and to improve the soil's bio-chemical conditions, especially when organic matter and earthworms were applied. By comparing the two plant species, few significant differences were observed in the soil characteristics; Cytisus scoparius improved soil nutrient content more than Paulownia tomentosa, which instead stimulated more soil microbial metabolism. Regarding the pollutants, Paulownia tomentosa was more efficient in reducing the heavy metal (Pb, Cr, Cd, Zn, Cu, Ni) content, while earthworms were particularly able to stimulate the processes involved in the decontamination of organic pollutants (hydrocarbons). This ecological approach, validated at a mesoscale level, has recently been transferred to a real scale situation to carry out the bioremediation of polluted soil in San Giuliano Terme Municipality (Pisa, Italy). PMID:22911348

  18. The Kwajalein bioremediation demonstration: Final technical report

    SciTech Connect

    Walker, J.R. Jr.; Walker, A.B.

    1994-12-01

    The US Army Kwajalein Atoll (USAKA) Base, located in the Republic of the Marshall Islands (RMI) in the east-central Pacific Ocean, has significant petroleum hydrocarbon contamination resulting from years of military activities. Because of its remoteness, the lack of on-site sophisticated remediation or waste disposal facilities, the amenability of petroleum hydrocarbons to biodegradation, and the year-round temperature favorable for microbial activity, USAKA requested, through the Hazardous Waste Remedial Actions Program (HAZWRAP), that a project be conducted to evaluate the feasibility of using bioremediation for environmental restoration of contaminated sites within the atoll. The project was conducted in four distinct phases: (1) initial site characterization and on-site biotreatability studies, (2) selection of the demonstration area and collection of soil columns, (3) laboratory column biotreatability studies, and (4) an on-site bioremediation demonstration. The results of phases (1) and (3) have been detailed in previous reports. This report summarizes the results of phases (1) and (3) and presents phases (2) and (4) in detail.

  19. Manufacturing of bioreactive nanofibers for bioremediation.

    PubMed

    Tong, Ho-Wang; Mutlu, Baris R; Wackett, Lawrence P; Aksan, Alptekin

    2014-08-01

    Recombinant Escherichia coli (E. coli) cells were successfully encapsulated in reactive membranes comprised of electrospun nanofibers that have biocompatible polyvinyl alcohol (PVA)-based cores entrapping the E. coli and silica-based, mechanically sturdy porous shells. The reactive membranes were produced in a continuous fashion using a coaxial electrospinning system coupled to a microfluidic timer that mixed and regulated the reaction time of the silica precursor and the PVA solution streams. A factorial design method was employed to investigate the effects of the three critical design parameters of the system (the flow rate of the core solution, protrusion of the core needle, and the viscosity of the core solution) and to optimize these parameters for reproducibly and continuously producing high-quality core/shell nanofibers. The feasibility of using the reactive membranes manufactured in this fashion for bioremediation of atrazine, a herbicide, was also investigated. The atrazine degradation rate (0.24 µmol/g of E. coli/min) of the encapsulated E. coli cells expressing the atrazine-dechlorinating enzyme AtzA was measured to be relatively close to that measured with the free cells in solution (0.64 µmol/g of E. coli/min). We show here that the low cost, high flexibility, water insolubility, and high degradation efficiency of the bioreactive membranes manufactured with electrospinning makes it feasible for their wide-spread use in industrial scale bioremediation of contaminated waters. PMID:24615064

  20. Bioremediation of chlorinated solvents and diesel soils

    SciTech Connect

    Huismann, S.S.; Peterson, M.A.; Jardine, R.J.

    1995-11-01

    The US Army, in a cooperative effort with the Tennessee Valley Authority (TVA) and its cooperator, ENSR, performed an innovative enhanced bioremediation project at Fort Gillem in Atlanta, Georgia. The objective of the project was to remediate six hundred cubic yards of soil affected by a mixture of chlorinated compounds and petroleum hydrocarbons which posed a threat to uppermost groundwater and private drinking water wells. ENSR completed a demonstration project to measure the effects of bioremediation on both chlorinated compounds (primarily TCE) and petroleum hydrocarbons ({number_sign}2 diesel). Contaminated soil was placed on top of a bermed polyethylene liner to construct an ex-situ biovault. Nutrients were added to the soil as it was loaded onto the liner. Contaminated soil was also used to construct a control vault. A methane barrier cover was placed over both piles. The cover was designed to prevent short circuiting of induced airflow in and around the enhanced pile, and to prevent the release of fugitive emissions from either pile.

  1. Trajectories of Microbial Community Function in Response to Accelerated Remediation of Subsurface Metal Contaminants

    SciTech Connect

    Firestone, Mary

    2015-01-14

    Objectives of proposed research were to; Determine if the trajectories of microbial community composition and function following organic carbon amendment can be related to, and predicted by, key environmental determinants; Assess the relative importance of the characteristics of the indigenous microbial community, sediment, groundwater, and concentration of organic carbon amendment as the major determinants of microbial community functional response and bioremediation capacity; and Provide a fundamental understanding of the microbial community ecology underlying subsurface metal remediation requisite to successful application of accelerated remediation and long-term stewardship of DOE-IFC sites.

  2. Healthy environments for healthy people: bioremediation today and tomorrow.

    PubMed Central

    Bonaventura, C; Johnson, F M

    1997-01-01

    Increases in environmental contamination lead to a progressive deterioration of environmental quality. This condition challenges our global society to find effective measures of remediation to reverse the negative conditions that severely threaten human and environmental health. We discuss the progress being made toward this goal through application of bioremediation techniques. Bioremediation generally utilizes microbes (bacteria, fungi, yeast, and algae), although higher plants are used in some applications. New bioremediation approaches are emerging based on advances in molecular biology and process engineering. Bioremediation continues to be the favored approach for processing biological wastes and avoiding microbial pathogenesis. Bioremediation may also play an increasing role in concentrating metals and radioactive materials to avoid toxicity or to recover metals for reuse. Microbes can biodegrade organic chemicals; purposeful enhancement of this natural process can aid in pollutant degradation and waste-site cleanup operations. Recently developed rapid-screening assays can identify organisms capable of degrading specific wastes and new gene-probe methods can ascertain their abundance at specific sites. New tools and techniques for use of bioremediation in situ, in biofilters, and in bioreactors are contributing to the rapid growth of this field. Bioremediation has already proven itself to be a cost-effective and beneficial addition to chemical and physical methods of managing wastes and environmental pollutants. We anticipate that it will play an increasingly important role as a result of new and emerging techniques and processes. Images Figure 3. PMID:9114274

  3. Healthy environments for healthy people: Bioremediation today and tomorrow

    SciTech Connect

    Bonaventura, C.; Johnson, F.M.

    1997-02-01

    Increases in environmental contamination lead to a progressive deterioration of environmental quality. This condition challenges our global society to find effective measures of remediation to reverse the negative conditions that severely threaten human and environmental health. We discuss the progress being made toward this goal through application of bioremediation techniques. Bioremediation generally utilizes microbes (bacteria, fungi, yeast, and algae), although higher plants are used in some applications. New bioremediation approaches are emerging based on advances in molecular biology and process engineering. Bioremediation continues to be the favored approach for processing biological wastes and avoiding microbial pathogenesis. Bioremediation may also play an increasing role in concentrating metals and radioactive materials to avoid toxicity or to recover metals for reuse. Microbes can biodegrade organic chemicals; purposeful enhancement of this natural process can aid in pollutant degradation and waste-site cleanup operations. Recently developed rapid-screening assays can identify organisms capable of degrading specific wastes and new gene-probe methods can ascertain their abundance at specific sites. New tools and techniques for use of bioremediation in situ, in biofilters, and in bioreactors are contributing to the rapid growth of this field. Bioremediation has already proven itself to be a cost-effective and beneficial addition to chemical and physical methods of managing wastes and environmental pollutants. We anticipate that it will play an increasingly important role as a result of new and emerging techniques and processes. 140 refs., 4 figs., 1 tab.

  4. Genetic analysis of stress responses in soil bacteria for enhanced bioremediation of mixed contaminants. 1998 annual progress report

    SciTech Connect

    Wong, K.K.

    1998-06-01

    'To realize the full potential of bioremediation, the individual bacterial responses to the stresses (lack of nutrients or oxygen; mixed pollutants) encountered at contaminated sites must be understood. This information can then be extrapolated to field applications using indigenous bacteria or genetically engineered micro-organisms. Studying bacterial response to stresses presents an opportunity for improving bioremediation strategies, both with indigenous populations and genetically engineered microbes, and should contribute to environmental management and restoration goals. Enhancing in-situ removal of hazardous wastes by stimulating the growth of indigenous bacteria with nutrients has been demonstrated. But how much and how often to apply these supplements has been difficult to determine, and controlled and reproducible degradation of pollutants in the environment has not yet been achieved. As of May 31st 1998, this report summarizes work after 17 months of a 36 month project.'

  5. Subsurface In Situ Elemental Composition Measurements with PING

    NASA Technical Reports Server (NTRS)

    Parsons, Ann; McClanahan, Timothy; Bodnarik, Julia; Evans, Larry; Nowicki, Suzanne; Schweitzer, Jeffrey; Starr, Richard

    2013-01-01

    This paper describes the Probing In situ with Neutron and Gamma rays (PING) instrument, that can measure the subsurface elemental composition in situ for any rocky body in the solar system without the need for digging into the surface. PING consists of a Pulsed Neutron Generator (PNG), a gamma ray spectrometer and neutron detectors. Subsurface elements are stimulated by high-energy neutrons to emit gamma rays at characteristic energies. This paper will show how the detection of these gamma rays results in a measurement of elemental composition. Examples of the basalt to granite ratios for aluminum and silicon abundance are provided.

  6. Bioremediation of hazardous wastes. Research, development, and field evaluations, 1995

    SciTech Connect

    Kremer, F.

    1995-09-01

    The U.S. Environmental Protection Agency`s (EPA`s) Office of Research and Development (ORD) hosted the eighth annual Symposium on Bioremediation of Hazardous Wastes: Research, Development, and Field Evaluations in Rye Brook, New York, August 8-10, 1995. In this document, abstracts of paper and poster presentations from the symposium are organized within five key research and program areas: Bioremediation Field Initiative; Field research; Performance evaluation; Pilot-scale research; and Process research. The last section of the document includes abstracts of presentations on bioremediation research performed as part of the Hazardous Substance Research Center (HSRC) program.

  7. Development and application of the lux gene for environmental bioremediation

    SciTech Connect

    Burlage, R.S.; Yang, Z.; Palmer, R.J.; Khang, Y.

    1996-09-01

    Bioremediation is the use of living systems, usually microorganisms, to treat a quantity of soil or water for the presence of hazardous wastes. Bioremediation has many advantages over other remediation approaches, including cost savings, versatility, and the ability to treat the wastes in situ. In order to study the processes of microbial bioremediation, the authors have constructed bacterial strains that incorporate genetically engineered bioreporter genes. These bioreporter genes allow the bacteria to be detected during in situ processes, as manifested by their ability to bioluminescence or to fluoresce. This bioreporter microorganisms are described, along with the technology for detecting them and the projects which are benefiting from their application.

  8. Trace Metal Bioremediation: Assessment of Model Components from Laboratory and Field Studies to Identify Critical Variables

    SciTech Connect

    Peter Jaffe; Herschel Rabitz

    2003-02-14

    bioremediation of trace metals was highly sensitive to the formulation of the denitrification process. Simulations were performed to illustrate the effect of biostimulation on the transport and precipitation of uranium in the subsurface, at conditions equivalent to UMTRA sites. These simulations predicted that uranium would precipitate in bands that are located relatively close to the acetate injection well. The simulations also showed the importance of properly determining U(IV) oxidative dissolution rates, in order to assess the stability of precipitates once oxygenated water reenters the aquifer after bioremediation is discontinued. The objective of this project was to provide guidance to NABIR's Systems Integration Element, on the development of models to simulate the bioremediation of trace metals and radionuclides. Such models necessarily need to integrate hydrological, geochemical, and microbiological processes. In order to gain a better understanding of the key processes that such a model should contain, it was deemed desirable to convene a workshop with experts from these different fields. The goal was to obtain a preliminary consensus on the required level of detail for the formulations of these different chemical, physical, and microbiological processes. The workshop was held on December 18, 1998.

  9. Containment of subsurface contaminants

    DOEpatents

    Corey, John C.

    1994-01-01

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

  10. Nonintrusive subsurface surveying capability

    SciTech Connect

    Tunnell, T.W.; Cave, S.P.

    1994-06-01

    This presentation describes the capabilities of a ground-pentrating radar (GPR) system developed by EG&G Energy Measurements (EM), a prime contractor to the Department of Energy (DOE). The focus of the presentation will be on the subsurface survey of DOE site TA-21 in Los Alamos, New Mexico. EG&G EM developed the system for the Department of Defense. The system is owned by the Department of the Army and currently resides at KO in Albuquerque. EM is pursuing efforts to transfer this technology to environmental applications such as waste-site characterization with DOE encouragement. The Army has already granted permission to use the system for the waste-site characterization activities.