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Sample records for aerobic mtbe biodegradation

  1. AEROBIC BIODEGRADATION OF GASOLINE OXYGENATES MTBE AND TBA

    EPA Science Inventory

    MTBE degradation was investigated using a continuously stirred tank reactor (CSTR) with biomass retention (porous pot reactor) operated under aerobic conditions. MTBE was fed to the reactor at an influent concentration of 150 mg/l (1.70 mmol/l). A second identifical rector was op...

  2. Evaluation and Optimization of MTBE Biodegradation in Aquifers, Final Report

    SciTech Connect

    Legler, T; Balser, L; Koester, C; Wilson, W

    2004-02-13

    This study was focused on meeting the following objectives concerning the process of methyl tertiary butyl ether (MTBE) biodegradation, with the goal of optimizing this process in situ: 1. Assess whether intrinsic bioattenuation of MTBE is feasible under aerobic conditions across several contaminated sites. 2. Determine the effect of co-contaminants, specifically water-soluble gasoline components (most notably benzene, toluene, ethylbenzene and xylenes [BTEX]) on MTBE biodegradation. 3. Determine whether microbial and/or chemical factors contribute to different MTBE degradative activities. 4. Isolate and characterize MTBE-degrading microorganisms from sediments in which MTBE biodegradation was observed.

  3. Factors Affecting the Success of Enhanced Aerobic Biodegradation of MTBE and BTEX

    NASA Astrophysics Data System (ADS)

    Landmeyer, J. E.; Bradley, P. M.

    2002-12-01

    At a gasoline-release site in South Carolina, a proprietary form of MgO2 injected into the subsurface in a former underground storage tank (UST) area to increase dissolved oxygen (DO) levels did not elevate low (0 mg/L) DO levels nor decrease concentrations of benzene, toluene, or methyl tert-butyl ether (MTBE). In contrast, MgO2 injected less than 200 meters downgradient rapidly increased DO, and benzene, toluene, and MTBE concentrations decreased up to 87%. These different results following oxygen addition to an anoxic fuel-contaminated aquifer can be related to differences in ambient hydrologic conditions between the two areas that supported different microbial communities with respect to contaminant degradation prior to oxygen-based remediation. For example, although fuel-contaminated ground water downgradient of the source area was anoxic, infiltration of DO-rich recharge occurred through overlying permeable sediments for some time before oxygen injection. In contrast, this natural input of DO does not occur in the paved, former UST area. Moreover, the absence of recharge in the source area permitted the accumulation of reduced mineral- and soluble-inorganic species, a significant oxygen sink that competed with contaminant biodegradation demand for the injected oxygen. This talk will describe the relation that exists between hydrologic and microbiologic conditions in contaminated shallow ground-water systems exhibited at this site, and why certain parameters should be measured as part of any oxygen-based remedial strategies.

  4. Laboratory evidence of MTBE biodegradation in Borden aquifer material

    NASA Astrophysics Data System (ADS)

    Schirmer, Mario; Butler, Barbara J.; Church, Clinton D.; Barker, James F.; Nadarajah, Nalina

    2003-02-01

    Mainly due to intrinsic biodegradation, monitored natural attenuation can be an effective and inexpensive remediation strategy at petroleum release sites. However, gasoline additives such as methyl tert-butyl ether (MTBE) can jeopardize this strategy because these compounds often degrade, if at all, at a slower rate than the collectively benzene, toluene, ethylbenzene and the xylene (BTEX) compounds. Investigation of whether a compound degrades under certain conditions, and at what rate, is therefore important to the assessment of the intrinsic remediation potential of aquifers. A natural gradient experiment with dissolved MTBE-containing gasoline in the shallow, aerobic sand aquifer at Canadian Forces Base (CFB) Borden (Ontario, Canada) from 1988 to 1996 suggested that biodegradation was the main cause of attenuation for MTBE within the aquifer. This laboratory study demonstrates biologically catalyzed MTBE degradation in Borden aquifer-like environments, and so supports the idea that attenuation due to biodegradation may have occurred in the natural gradient experiment. In an experiment with batch microcosms of aquifer material, three of the microcosms ultimately degraded MTBE to below detection, although this required more than 189 days (or >300 days in one case). Failure to detect the daughter product tert-butyl alcohol (TBA) in the field and the batch experiments could be because TBA was more readily degradable than MTBE under Borden conditions.

  5. 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 ...

  6. 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 ...

  7. FIELD OBSERVATIONS TO RECOGNIZE THE NATURAL BIODEGRADATION OF MTBE

    EPA Science Inventory

    At some gasoline spill sites (perhaps a third of sites nationwide) MTBE in ground water has been biologically degraded to TBA. This natural biodegradation of MTBE contributes to the natural attenuation of MTBE, but it produces TBA as a potential contaminant. Under ordinary cond...

  8. MTBE BIODEGRADATION IN A GRAVITY FLOW, HIGH-BIOMASS RETAINING BIOREACTOR

    EPA Science Inventory

    The aerobic biodegradation of methyl tert-butyl ether (MtBE), a widely used fuel oxygenate, was investigated using a pilot-scale biomass-retaining bioreactor called a Biomass Concentrator Reactor (BCR). The reactor was operated for a year at a flow rate of 2500 L/d on Ci...

  9. EVALUATING NATURAL BIODEGRADATION OF MTBE AT MULTIPLE UST SITES

    EPA Science Inventory

    Until very recently, methyl t-butyl ether (MTBE) was considered non-biodegradable in the subsurface. This has been an impediment in applying remediation by natural attenuation (RNA) as a remedial strategy at MTBE-impacted sites. Although a number of recent studies have demonst...

  10. Biodegradation of MTBE by indigenous aquifer microorganisms under artificial oxic conditions

    USGS Publications Warehouse

    Landmeyer, J.E.; Bradley, P.M.

    2001-01-01

    The hypothesis that artificial oxic conditions will lead to MTBE biodegradation by indigenous microorganisms in anoxic, gasoline-contaminated aquifers was examined by adding oxygen in the form of a metal peroxide slurry to an anoxic part of gasoline-contaminated aquifer in South Carolina. Field observations of relatively rapid aerobic MTBE biodegradation following oxygen addition suggest that the indigenous bacteria have become acclimated not only to mg/L concentrations of MTBE in the gasoline plume, but also to periodic delivery of oxygen by recharge events. Significant natural attenuation of MTBE could occur if the oxygen limitations naturally associated with gasoline releases can be removed, either under natural conditions where discharging anoxic groundwater comes into contact with oxygen, or artificial conditions where oxygen can be added to aquifers containing mg/L concentrations of MTBE. This final solution might be an effective strategy for intercepting characteristically long MTBE plumes, particularly at sites not characterized by groundwater discharge to land surface. This is an abstract of a paper presented at the 222nd ACS National Meting (Chicago, IL 8/26-30/2001).

  11. BTE-OX biodegradation kinetics with MTBE through bioaugmentation.

    PubMed

    Acuna-Askar, K; Villarreal-Chiu, J F; Gracia-Lozano, M V; Garza-Gonzalez, M T; Chavez-Gomez, B; Rodriguez-Sanchez, I P; Barrera-Saldana, H A

    2004-01-01

    The biodegradation kinetics of BTE-oX and MTBE, mixed all together, in the presence of bioaugmented bacterial populations as high as 880 mg/L VSS was evaluated. The effect of soil in aqueous samples and the effect of Tergitol NP-10 on substrate biodegradation rates were also evaluated. Biodegradation kinetics was evaluated for 36 hours, every 6 hours. Benzene and o-xylene biodegradation followed a first-order one-phase kinetic model, whereas toluene and ethylbenzene biodegradation was well described by a first-order two-phase kinetic model in all samples. MTBE followed a zero-order removal kinetic model in all samples. The presence of soil in aqueous samples retarded BTE-oX removal rates, with the highest negative effect on o-xylene. The presence of soil enhanced MTBE removal rate. The addition of Tergitol NP-10 to aqueous samples containing soil had a positive effect on substrate removal rate in all samples. Substrate percent removals ranged from 95.4-99.7% for benzene, toluene and ethylbenzene. O-xylene and MTBE percent removals ranged from 55.9-90.1% and 15.6-30.1%, respectively. PMID:15497834

  12. ANAEROBIC BIODEGRADATION OF MTBE AT A GASOLINE SPILL SITE

    EPA Science Inventory

    To manage risk or to implement natural attenuation as a remedy, regulatory agencies must understand the processes that attenuate methyl-tert-butyl ether (MTBE) in ground water. Most case studies and laboratory studies in the literature indicate that natural biodegradation is not ...

  13. USING δ13C TO PREDICT THE RATE OF BIODEGRADATION OF MTBE

    EPA Science Inventory

    It is difficult to estimate the rate of natural biodegradation of MTBE at field scale. Dispersion in the aquifer or dilution in the well can give a false impression of attenuation along a flow path. The first product of MTBE biodegradation is TBA. Many gasoline spills contain TB...

  14. ANALYSIS OF AN AEROBIC FLUIDIZED BED REACTOR DEGRADING MTBE AND BTEX AT REDUCED EBCTS

    EPA Science Inventory

    The purpose of this study was to investigate the biodegradation of MTBE and BTEX using a fluidized bed reactor (FBR) with granular activated carbon (GAC) as a biological attachment medium. Batch experiments were run to analyze the MTBE and TBA degradation kinetics of the culture ...

  15. USE OF MEMBRANE BIOREACTOR FOR BIODEGRADATION OF MTBE IN CONTAMINATED WATER1

    EPA Science Inventory

    An ultrafiltration membrane bioreactor was evaluated for biodegradation of methyl tert-butyl ether (MTBE) in contaminated water. The system was fed 5 mg/L MTBE in granular activated carbon (GAC) treated Cincinnati tap water containing ample buffer and nutrients. Within 120...

  16. USING STABLE CARBON ISOTOPES TO ESTIMATE THE RATE OF NATURAL BIODEGRADATION OF MTBE AT FIELD SCALE

    EPA Science Inventory

    Natural biodegradation of fuel contaminants in ground water reduces the risk of contamination of drinking water wells. It is very difficult to estimate the natural rate of biodegradation of MTBE in ground water because its primary biodegradation product, TBA, is also a component...

  17. MICROCOSM STUDY OF ANAEROBIC BIODEGRADATION OF MTBE AND TBA

    EPA Science Inventory

    Ground water samples collected in at a gasoline spill sites in Orange County, California, suggested that MTBE was being transformed to TBA. In some of the most heavily contaminated wells, the concentration of TBA was higher than the concentration of MTBE (MTBE 2 µg/L and TBA 40,...

  18. Aerobic mineralization of MTBE and tert-butyl alcohol by stream-bed sediment microorganisms

    USGS Publications Warehouse

    Bradley, P.M.; Landmeyer, J.E.; Chapelle, F.H.

    1999-01-01

    Microorganisms indigenous to the stream-bed sediments at two gasoline- contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-14C]-MTBE and 84% of [U-14C]-TBA were degraded to 14CO2 under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.Microorganisms indigenous to the stream-bed sediments at two gasoline-contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-14C]-MTBE and 84% of [U-14C]-TBA were degraded to 14CO2 under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.

  19. Effect of redox conditions on MTBE biodegradation in surface water Sediments

    USGS Publications Warehouse

    Bradley, P.M.; Chapelle, F.H.; Landmeyer, J.E.

    2001-01-01

    Microbial degradation of methyl tert-butyl ether (MTBE) was observed in surface water-sediment microcosms under anaerobic conditions. The efficiency and products of anaerobic MTBE biodegradation were dependent on the predominant terminal electron-accepting conditions. In the presence of substantial methanogenic activity, MTBE biodegradation was nominal and involved reduction of MTBE to the toxic product, tert-butyl alcohol (TBA). In the absence of significant methanogenic activity, accumulation of [14C]TBA generally decreased, and mineralization of [U-14C]MTBE to 14CO2 generally increased as the oxidative potential of the predominant terminal electron acceptor increased in the order of SO4, Fe(III), Mn(IV) < NO3 < O2. Microbial mineralization of MTBE to CO2 under Mn(IV)or SO4-reducing conditions has not been reported previously. The results of this study indicate that microorganisms inhabiting the sediments of streams and lakes can degrade MTBE effectively under a range of anaerobic terminal electron-accepting conditions. Thus, anaerobic bed sediment microbial processes may provide a significant environmental sink for MTBE in surface water systems throughout the United States.

  20. Effect of soil and a nonionic surfactant on BTE-oX and MTBE biodegradation kinetics.

    PubMed

    Acuna-Askar, K; Gracia-Lozano, M V; Villarreal-Chiu, J F; Marmolejo, J G; Garza-Gonzalez, M T; Chavez-Gomez, B

    2005-01-01

    The biodegradation kinetics of BTE-oX and MTBE, mixed all together, in the presence of 905 mg/L VSS of BTEX-acclimated biomass was evaluated. Effects of soil and Tergitol NP-10 in aqueous samples on substrate biodegradation rates were also evaluated. Biodegradation kinetics was evaluated for 36 hours, every 6 hours. MTBE biodegradation followed a first-order one-phase kinetic model in all samples, whereas benzene, toluene and ethylbenzene biodegradation followed a first-order two-phase kinetic model in all samples. O-xylene biodegradation followed a first-order two-phase kinetic model in the presence of biomass only. Interestingly, o-xylene biodegradation was able to switch to a first-order one-phase kinetic model when either soil or soil and Tergitol NP-10 were added. The presence of soil in aqueous samples retarded benzene, toluene and ethylbenzene removal rates. O-xylene and MTBE removal rates were enhanced by soil. The addition of Tergitol NP-10 to aqueous samples containing soil had a positive effect on substrate removal rate in all samples. Substrate percent removals ranged 77-99.8% for benzene, toluene and ethylbenzene. O-xylene and MTBE percent removals ranged 50.1-65.3% and 9.9-43.0%, respectively. PMID:16312957

  1. Biodegradation kinetics of BTE-OX and MTBE by a diesel-grown biomass.

    PubMed

    Acuna-Askar, K; de la Torre-Torres, M A; Guerrero-Munoz, M J; Garza-Gonzalez, M T; Chavez-Gomez, B; Rodriguez-Sanchez, I P; Barrera-Saldana, H A

    2006-01-01

    The biodegradation kinetics of BTE-oX and MTBE, mixed all together in the presence of diesel-grown bioaugmented bacterial populations as high as 885 mg/L VSS, was evaluated. The effect of soil in aqueous samples and the effect of Tergitol NP-10 on substrate biodegradation rates were also evaluated. Biodegradation kinetics was evaluated for 54 h, every 6 h. All BTE-oX chemicals followed a first-order two-phase biodegradation kinetic model, whereas MTBE followed a zero-order removal kinetic model in all samples. BTE-oX removal rates were much higher than those of MTBE in all samples. The presence of soil in aqueous samples retarded BTE-oX and MTBE removal rates. The addition of Tergitol NP-10 to aqueous samples containing soil had a positive effect on substrate removal rate in all samples. Substrate percent removals ranged between 64.8-98.9% for benzene, toluene and ethylbenzene. O-xylene and MTBE percent removals ranged between 18.7-40.8% and 7.2-10.3%, respectively. PMID:16862790

  2. Biodegradation of MTBE by indigenous aquifer microorganisms under artificial oxic conditions

    USGS Publications Warehouse

    Landmeyer, J.E.; Bradley, P.M.

    2001-01-01

    Oxygen in the form of a metal peroxide slurry (MgO2 and water) was added to an anoxic part of a gasoline-contaminated aquifer in South Carolina to test the hypothesis that artificial oxic conditions will lead to MTBE biodegradation by indigenous microorganisms in anoxic, gasoline-contaminated aquifers. The slurry slowly released dissolved oxygen upon hydrolysis with groundwater, and was a proprietary mixture consisting of ??? 25-35 wt % MgO2. Significant natural attenuation of MTBE could occur if the oxygen limitations naturally associated with gasoline releases could be removed, either under natural conditions where discharging anoxic groundwater comes into contact with oxygen, or artificial conditions where oxygen could be added to aquifers containing milligram per liter concentrations of MTBE. This final solution might be an effective strategy for intercepting characteristically long MTBE plumes, particularly at those sites not characterized by groundwater discharge to land surface.

  3. SUMMARY OF WORKSHOP ON BIODEGRADATION OF MTBE FEBRUARY 1-3, 2000

    EPA Science Inventory

    A workshop on biodegradation of methyl tert butyl ether (MTBE) contaminated soils and groundwater was held in Cincinnati, Ohio, February 1-2, 2000, and was sponsored by the USEPA's NRMRL and the American Petroleum Institute. Researchers in academia, industry, and government were ...

  4. TBA IN GROUND WATER FROM THE NATURAL BIODEGRADATION OF MTBE

    EPA Science Inventory

    At many UST spills, the concentrations of TBA in ground water are much higher than would be expected from the presence of TBA in the gasoline originally spilled. The ratio of concentrations of TBA to concentrations of MTBE in monitoring wells at gasoline spill sites was compared ...

  5. IS YOUR TBA COMING FROM BIODEGRADATION OF MTBE

    EPA Science Inventory

    MTBE (methyl tertiary butyl ether) is present at high concentrations in ground water at many sites where gasoline has been spilled from underground storage tanks. In addition, TBA (tertiary butyl alcohol) is also present at high concentrations in many of the same ground waters. ...

  6. Aerobic biodegradation of trichloroethene without auxiliary substrates.

    PubMed

    Schmidt, Kathrin R; Gaza, Sarah; Voropaev, Andrey; Ertl, Siegmund; Tiehm, Andreas

    2014-08-01

    Trichloroethene (TCE) represents a priority pollutant and is among the most frequently detected contaminants in groundwater. The current bioremediation measures have certain drawbacks like e.g. the need for auxiliary substrates. Here, the aerobic biodegradation of TCE as the sole growth substrate is demonstrated. This new process of metabolic TCE degradation was first detected in groundwater samples. TCE degradation was stable in an enriched mixed bacterial culture in mineral salts medium for over five years and repeated transfers of the culture resulting in a 10(10) times dilution of the original groundwater. Aerobic TCE degradation resulted in stoichiometric chloride formation. Stable carbon isotope fractionation was observed providing a reliable analytical tool to assess this new biodegradation process at field sites. The results suggest that aerobic biodegradation of TCE without auxiliary substrate could be considered as an option for natural attenuation or engineered bioremediation of contaminated sites. PMID:24793109

  7. ENRICHMENT OF STABLE CARBON AND HYDROGEN ISOTOPES DURING ANAEROBIC BIODEGRADATION OF MTBE-MICROCOSM AND FIELD EVIDENCE

    EPA Science Inventory

    The conventional approach to evaluate biodegradation of organic contaminants in ground water is to demonstrate an increase in the concentration of transformation products. This approach is problematic for MTBE from gasoline spills because the primary transformation product (TBA) ...

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

    NASA Astrophysics Data System (ADS)

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

    2006-06-01

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

  9. New Routes for Aerobic Biodegradation of Dimethylsulfoniopropionate

    PubMed Central

    Taylor, Barrie F.; Gilchrist, Darrin C.

    1991-01-01

    Dimethylsulfoniopropionate (DMSP), an osmolyte in marine plants, is biodegraded by cleavage of dimethyl sulfide (DMS) or by demethylation to 3-methiolpropionate (MMPA) and 3-mercaptopropionate (MPA). Sequential demethylation has been observed only with anoxic slurries of coastal sediments. Bacteria that grew aerobically on MMPA and DMSP were isolated from marine environments and phytoplankton cultures. Enrichments with DMSP selected for bacteria that generated DMS, whereas MMPA enrichments selected organisms that produced methanethiol (CH3SH) from either DMSP or MMPA. A bacterium isolated on MMPA grew on MMPA and DMSP, but rapid production of CH3SH from DMSP occurred only with DMSP-grown cells. Low levels of MPA accumulated during growth on MMPA, indicating demethylation as well as demethiolation of MMPA. The alternative routes for DMSP biodegradation via MMPA probably impact on net DMS fluxes to the marine atmosphere. PMID:16348607

  10. 40 CFR 796.3100 - Aerobic aquatic biodegradation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 32 2014-07-01 2014-07-01 false Aerobic aquatic biodegradation. 796.3100 Section 796.3100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Transformation Processes § 796.3100 Aerobic aquatic biodegradation. (a)...

  11. 40 CFR 796.3100 - Aerobic aquatic biodegradation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 33 2012-07-01 2012-07-01 false Aerobic aquatic biodegradation. 796.3100 Section 796.3100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Transformation Processes § 796.3100 Aerobic aquatic biodegradation. (a)...

  12. 40 CFR 796.3100 - Aerobic aquatic biodegradation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Aerobic aquatic biodegradation. 796.3100 Section 796.3100 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Transformation Processes § 796.3100 Aerobic aquatic biodegradation. (a)...

  13. Characterization and aerobic biodegradation of selected monoterpenes

    SciTech Connect

    Misra, G.; Pavlostathis, S.G.; Li, J.; Purdue, E.M.

    1996-12-31

    Monoterpenes are biogenic chemicals and occur in abundance in nature. Large-scale industrial use of these chemicals has recently been initiated in an attempt to replace halogenated solvents and chlorofluorocarbons which have been implicated in the stratospheric depletion of ozone. This study examined four hydrocarbon monoterpenes (d-limonene, {alpha}-pinene, {gamma}-terpinene, and terpinolene) and four alcohols (arbanol, linalool, plinol, and {alpha}-terpineol). Water solubility, vapor pressure, and octanol/water partition coefficients were estimated. Aerobic biodegradability tests were conducted in batch reactors by utilizing forest soil extract and enriched cultures as inoculum. The hydrophobic nature and high volatility of the hydrocarbons restricted the investigation to relatively low aqueous concentrations. Each monoterpene was analyzed with a gas chromatograph equipped with a flame ionization detector after extraction from the aqueous phase with isooctane. Terpene mineralization was tested by monitoring liquid-phase carbon, CO{sub 2} production and biomass growth. All four hydrocarbons and two alcohols readily degraded under aerobic conditions. Plinol resisted degradation in assays using inocula from diverse sources, while arbanol degraded very slowly. The intrinsic biokinetics coefficients for the degradation of d-limonene and {alpha}-terpineol were estimated by using cultures enriched with the respective monoterpenes. Monoterpene biodegradation followed Monod kinetics.

  14. Role of back diffusion and biodegradation reactions in sustaining an MTBE/TBA plume in alluvial media

    USGS Publications Warehouse

    Rasa, Ehsan; Chapman, Steven W.; Bekins, Barbara A.; Fogg, Graham E.; Scow, Kate M.; Mackay, Douglas M.

    2011-01-01

    A methyl tert-butyl ether (MTBE) / tert-butyl alcohol (TBA) plume originating from a gasoline spill in late 1994 at Vandenberg Air Force Base (VAFB) persisted for over 15 years within 200 feet of the original spill source. The plume persisted until 2010 despite excavation of the tanks and piping within months after the spill and excavations of additional contaminated sediments from the source area in 2007 and 2008. The probable history of MTBE concentrations along the plume centerline at its source was estimated using a wide variety of available information, including published details about the original spill, excavations and monitoring by VAFB consultants, and our own research data. Two-dimensional reactive transport simulations of MTBE along the plume centerline were conducted for a 20-year period following the spill. These analyses suggest that MTBE diffused from the thin anaerobic aquifer into the adjacent anaerobic silts and transformed to TBA in both aquifer and silt layers. The model reproduces the observation that after 2004 TBA was the dominant solute, diffusing back out of the silts into the aquifer and sustaining plume concentrations much longer than would have been the case in the absence of such diffusive exchange. Simulations also suggest that aerobic degradation of MTBE or TBA at the water table in the overlying silt layer significantly affected concentrations of MTBE and TBA by limiting the chemical mass available for back diffusion to the aquifer.

  15. Role of back diffusion and biodegradation reactions in sustaining an MTBE/TBA plume in alluvial media

    PubMed Central

    Rasa, Ehsan; Chapman, Steven W.; Bekins, Barbara A.; Fogg, Graham E.; Scow, Kate M.; Mackay, Douglas M.

    2012-01-01

    A methyl tert-butyl ether (MTBE) / tert-butyl alcohol (TBA) plume originating from a gasoline spill in late 1994 at Vandenberg Air Force Base (VAFB) persisted for over 15 years within 200 feet of the original spill source. The plume persisted until 2010 despite excavation of the tanks and piping within months after the spill and excavations of additional contaminated sediments from the source area in 2007 and 2008. The probable history of MTBE concentrations along the plume centerline at its source was estimated using a wide variety of available information, including published details about the original spill, excavations and monitoring by VAFB consultants, and our own research data. Two-dimensional reactive transport simulations of MTBE along the plume centerline were conducted for a 20-year period following the spill. These analyses suggest that MTBE diffused from the thin anaerobic aquifer into the adjacent anaerobic silts and transformed to TBA in both aquifer and silt layers. The model reproduces the observation that after 2004 TBA was the dominant solute, diffusing back out of the silts into the aquifer and sustaining plume concentrations much longer than would have been the case in the absence of such diffusive exchange. Simulations also suggest that aerobic degradation of MTBE or TBA at the water table in the overlying silt layer significantly affected concentrations of MTBE and TBA by limiting the chemical mass available for back diffusion to the aquifer. PMID:22115089

  16. Analysis of the Pilot Biodegradation of MTBE Study at a Shell Station in Moorestown, New Jersey

    NASA Astrophysics Data System (ADS)

    Castellucci, M.; Sun, H.; Ingersoll, W.

    2004-05-01

    "Under-performance of the system" was reported for a pilot biodegradation project to limit the migration of MTBE and BTEX at a Shell gasoline spill site in Moorestown, New Jersey, while a very successful bioremediation pilot project was reported by the same research group using the same method in one of their California's study sites. The two prime factors for the "under- performance of the system" in the New Jersey site mentioned in the report submitted to New Jersey Department of Environmental Protection (NJDEP) by Equilon Enterprises LLC (Houston) are, "oxygen distribution within the biobarrier systems and unusual site pH conditions". Also, it seems the same type of microbe mixed culture is very efficient at degrading MTBE in a laboratory environmental setting. This prompts us to think that in addition to the difference of aquifer characteristics, the year-round general soil-water environmental differences between California and New Jersey may be a more significant factor than they realized. The temperature of the surface water, which we think is close to the soil water temperature, from the data points we selected adjacent to the sites, rarely reaches over 31 0C in summer and reaches close to freezing point in December to February in New Jersey. On the contrary, the temperature in the California's water data we examined rarely dips close to freezing point. It gets warmer down the middle and south part of the CA State. Also, the water pH we examined corresponds positively to the surface water temperature, though a slight lag is shown in the data. The highest pH is seen in the summer and fall, and the lowest pH is seen in the winter and spring months. The pH change in response to seasonal temperature change seems also being shown in the data reported from the monitoring wells in this NJ remediation site. Based on Equilon Enterpreises LLC's report, lower pH will hamper the function and growth of the injected microbes. Though, we did not read any reports on the

  17. Application of Stable Carbon Isotope Ratios to Recognize Natural Biodegradation of MTBE

    EPA Science Inventory

    The organisms that degrade MTBE under anaerobic conditions are evolved to acquire energy for growth by using molecular hydrogen and carbonate ion to cleave methyl ether bonds. Methyl ether bonds are common in nature and the bond also occurs in MTBE. MTBE in contaminated ground...

  18. ROLE OF MTBE MNA IN UNDERSTANDING THE SIGNIFICANCE OF SMALL RELEASES

    EPA Science Inventory

    There are a variety of processes that can contribute the natural attenuation of MTBE in ground water that has been impacted by a small release of gasoline. The contribution of aerobic biodegradation can be distinguished from the contribution of anaerobic biodegradation by compar...

  19. Evaluation of Biodegradability of Waste Before and After Aerobic Treatment

    NASA Astrophysics Data System (ADS)

    Suchowska-Kisielewicz, Monika; Jędrczak, Andrzej; Sadecka, Zofia

    2014-12-01

    An important advantage of use of an aerobic biostabilization of waste prior to its disposal is that it intensifies the decomposition of the organic fraction of waste into the form which is easily assimilable for methanogenic microorganisms involved in anaerobic decomposition of waste in the landfill. In this article it is presented the influence of aerobic pre-treatment of waste as well as leachate recirculation on susceptibility to biodegradation of waste in anaerobic laboratory reactors. The research has shown that in the reactor with aerobically treated waste stabilized with recilculation conversion of the organic carbon into the methane is about 45% higher than in the reactor with untreated waste stabilized without recirculation.

  20. Aerobic biodegradation of vinyl chloride in groundwater samples

    SciTech Connect

    Davis, J.W.; Carpenter, C.L. )

    1990-12-01

    Studies were conducted to examine the biodegradation of {sup 14}C-labeled vinyl chloride in samples taken from a shallow aquifer. Under aerobic conditions, vinyl chloride was readily degraded, with greater than 99% of the labeled material being degraded after 108 days and approximately 65% being mineralized to {sup 14}CO{sub 2}.

  1. Comparison of Aerobic and Anaerobic Biodegradation of Sugarcane Vinasse.

    PubMed

    Mota, V T; Araújo, T A; Amaral, M C S

    2015-07-01

    Vinasse is the main liquid waste from ethanol production, and it has a considerable pollution potential. Biological treatment is a promising alternative to reduce its organic load. The aim of this study was to analyze the biodegradation of sugarcane juice vinasse in aerobic and anaerobic conditions. The content of carbohydrates, proteins and volatile fatty acids was evaluated. Vinasse samples showed a high biodegradability (>96.5 %) and low percentage of inert chemical oxygen demand (COD) (<3.2 %) in both aerobic and anaerobic conditions. The rates of substrate utilization were slightly higher in aerobic reactors, but COD stabilization occurred simultaneously in the anaerobic reactors, confirming its suitability for anaerobic digestion. Inert COD in anaerobic conditions was lower than in aerobic conditions. On the other hand, COD from metabolic products in the anaerobic reactors was higher than in the aerobic ones, indicating an increased release of soluble microbial products (SMPs) by anaerobic microorganisms. The results indicated that carbohydrates were satisfactorily degraded and protein-like substances were the major components remaining after biological degradation of vinasse. PMID:25957273

  2. Biodegradation of Asphalt Cement-20 by Aerobic Bacteria

    PubMed Central

    Pendrys, John P.

    1989-01-01

    Seven gram-negative, aerobic bacteria were isolated from a mixed culture enriched for asphalt-degrading bacteria. The predominant genera of these isolates were Pseudomonas, Acinetobacter, Alcaligenes, Flavimonas, and Flavobacterium. The mixed culture preferentially degraded the saturate and naphthene aromatic fractions of asphalt cement-20. A residue remained on the surface which was resistant to biodegradation and protected the underlying asphalt from biodegradation. The most potent asphalt-degrading bacterium, Acinetobacter calcoaceticus NAV2, excretes an emulsifier which is capable of emulsifying the saturate and naphthene aromatic fractions of asphalt cement-20. This emulsifier is not denatured by phenol. PMID:16347928

  3. Parallel pathways of ethoxylated alcohol biodegradation under aerobic conditions.

    PubMed

    Zembrzuska, Joanna; Budnik, Irena; Lukaszewski, Zenon

    2016-07-01

    Non-ionic surfactants (NS) are a major component of the surfactant flux discharged into surface water, and alcohol ethoxylates (AE) are the major component of this flux. Therefore, biodegradation pathways of AE deserve more thorough investigation. The aim of this work was to investigate the stages of biodegradation of homogeneous oxyethylated dodecanol C12E9 having 9 oxyethylene subunits, under aerobic conditions. Enterobacter strain Z3 bacteria were chosen as biodegrading organisms under conditions with C12E9 as the sole source of organic carbon. Bacterial consortia of river water were used in a parallel test as an inoculum for comparison. The LC-MS technique was used to identify the products of biodegradation. Liquid-liquid extraction with ethyl acetate was selected for the isolation of C12E9 and metabolites from the biodegradation broth. The LC-MS/MS technique operating in the multiple reaction monitoring (MRM) mode was used for quantitative determination of C12E9, C12E8, C12E7 and C12E6. Apart from the substrate, the homologues C12E8, C12E7 and C12E6, being metabolites of C12E9 biodegradation by shortening of the oxyethylene chain, as well as intermediate metabolites having a carboxyl end group in the oxyethylene chain (C12E8COOH, C12E7COOH, C12E6COOH and C12E5COOH), were identified. Poly(ethylene glycols) (E) having 9, 8 and 7 oxyethylene subunits were also identified, indicating parallel central fission of C12E9 and its metabolites. Similar results were obtained with river water as inoculum. It is concluded that AE, under aerobic conditions, are biodegraded via two parallel pathways: by central fission with the formation of PEG, and by Ω-oxidation of the oxyethylene chain with the formation of carboxylated AE and subsequent shortening of the oxyethylene chain by a single unit. PMID:27037882

  4. Use of Mycobacterium austroafricanum IFP 2012 in a MTBE-degrading bioreactor.

    PubMed

    Maciel, Helena; Mathis, Hugues; Lopes Ferreira, Nicolas; Lyew, Darwin; Guiot, Serge; Monot, Frédéric; Greer, Charles W; Fayolle-Guichard, Françoise

    2008-01-01

    Mycobacterium austroafricanum IFP 2012 is able to slowly grow on methyl tert-butyl ether (MTBE), a fuel oxygenate widely used as a gasoline additive. The potential of M. austroafricanum IFP 2012 for aerobic MTBE degradation was investigated in the presence of a secondary carbon source, isopropanol. The strain was then tested for MTBE biodegradation at the laboratory-scale in a fixed-bed reactor using perlite as the matrix, and isopropanol was injected once a week to maintain M. austroafricanum IFP 2012 biomass inside the perlite bed. The biofilter was operated for 85 days at an influent flow rate of 20 ml/h by varying the MTBE concentration from 10 to 20 mg/l. The hydraulic retention time was fixed at 5 days. The removal of MTBE depended on the inlet MTBE concentration and a MTBE removal efficiency higher than 99% was obtained for MTBE concentrations up to 15 mg/l. A set of 16S rRNA gene primers specific for M. austroafricanum species was used to analyze the DNA extracted from the biofilter effluent in order to detect the presence of M. austroafricanum IFP 2012 and to estimate the effect of periodic injections of isopropanol on the release of the strain from the perlite bed. The results demonstrated that the injection of isopropanol served to maintain an active MTBE degrading biomass in the biofilter and that this system could be used to effectively treat MTBE contaminated groundwater. PMID:18685271

  5. APPLICATION OF STABLE CARBON AND HYDROGEN ISOTOPIC TECHNIQUES FOR MONITORING BIODEGRADATION OF MTBE IN THE FIELD

    EPA Science Inventory


    A significant challenge in environmental studies is to determine the onset and extent of MTBE bioremediation at an affected site, which may involve indirect approaches such as microcosm verification of microbial activities at a given site. Stable isotopic fractionation is cha...

  6. BIODEGRADATION OF METHYL TERT-BUTYL ETHER USING AN INNOVATIVE BIOMASS CONCENTRATOR REACTOR

    EPA Science Inventory

    The aerobic biodegradation of methyl tert-butyl ether (MTBE) was investigated using a pilot-scale Biomass Concentrator Reactor (BCR). The reactor was operated for a year at a flow rate of 2500 L/d of Cincinnati dechlorinated tap water and an influent MTBE concentration o...

  7. Stable carbon isotope fractionation during aerobic biodegradation of chlorinated ethenes

    SciTech Connect

    Chu, Kung-Hui; Mahendra, Shaily; Song, Donald L.; Conrad, Mark E.; Alvarez-Cohen, Lisa

    2003-06-01

    Stable isotope analysis is recognized as a powerful tool for monitoring, assessing, and validating in-situ bioremediation processes. In this study, kinetic carbon isotope fractionation factors () associated with the aerobic biodegradation of vinyl chloride (VC), cis-1,2-dichloroethylene (cDCE), and trichloroethylene (TCE) were examined. Of the three solvents, the largest fractionation effects were observed for biodegradation of VC. Both metabolic and cometabolic VC degradation were studied using Mycobacterium aurum L1 (grown on VC), Methylosinus trichosporium OB3b (grown on methane), Mycobacterium vaccae JOB 5 (grown on propane), and two VC enrichment cultures seeded from contaminated soils of Alameda Point and Travis Air Force Base, CA. M. aurum L1 caused the greatest fractionation (= -5.7) while for the cometabolic cultures, values ranged from -3.2 to -4.8. VC fractionation patterns for the enrichment cultures were within the range of those observed for the metabolic and cometabolic cultures (= -4.5 to -5.5). The fractionation for cometabolic degradation of TCE by Me. trichosporium OB3b was low (= -1.1), while no quantifiable carbon isotopic fractionation was observed during the cometabolic degradation of cDCE. For all three of the tested chlorinated ethenes, isotopic fractionation measured during aerobic degradation was significantly smaller than that reported for anaerobic reductive dechlorination. This study suggests that analysis of compound-specific isotopic fractionation could assist in determining whether aerobic or anaerobic degradation of VC and cDCE predominates in field applications of in-situ bioremediation. In contrast, isotopic fractionation effects associated with metabolic and cometabolic reactions are not sufficiently dissimilar to distinguish these processes in the field.

  8. In situ stimulation of aerobic PCB biodegradation in Hudson River sediments

    SciTech Connect

    Harkness, M.R.; McDermott, J.B.; Abramowicz, D.A.; Salvo, J.J.; Flanagan, W.P.; Stephens, M.L.; Mondello, F.J.; May, R.J.; Lobos, J.H.; Carroll, K.M.; Brennan, M.J.; Bracco, A.A.; Fish, K.M.; Warner, G.L.; Wilson, P.R.; Dietrich, D.K.; Lin, D.T.; Morgan, C.B.; Gately, W.L. )

    1993-01-22

    A 73-day field study of in situ aerobic biodegradation of polychlorinated biphenyls (PCBs) in the Hudson River shows that indigenous aerobic microorganisms can degrade the lightly chlorinated PCBs present in these sediments. Addition of inorganic nutrients, biphenyl, and oxygen enhanced PCB biodegradation, as indicated both by a 37 to 55 percent loss of PCBs and by the production of chlorobenzoates, intermediates in the PCB biodegradation pathway. Repeated inoculation with a purified PCB-degrading bacterium failed to improve biodegradative activity. Biodegradation was also observed under mixed but unamended conditions, which suggests that this process may occur commonly in river sediments, with implications for PCB fate models and risk assessments.

  9. Aerobic biodegradation of organic compounds in hydraulic fracturing fluids.

    PubMed

    Kekacs, Daniel; Drollette, Brian D; Brooker, Michael; Plata, Desiree L; Mouser, Paula J

    2015-07-01

    Little is known of the attenuation of chemical mixtures created for hydraulic fracturing within the natural environment. A synthetic hydraulic fracturing fluid was developed from disclosed industry formulas and produced for laboratory experiments using commercial additives in use by Marcellus shale field crews. The experiments employed an internationally accepted standard method (OECD 301A) to evaluate aerobic biodegradation potential of the fluid mixture by monitoring the removal of dissolved organic carbon (DOC) from an aqueous solution by activated sludge and lake water microbial consortia for two substrate concentrations and four salinities. Microbial degradation removed from 57 % to more than 90 % of added DOC within 6.5 days, with higher removal efficiency at more dilute concentrations and little difference in overall removal extent between sludge and lake microbe treatments. The alcohols isopropanol and octanol were degraded to levels below detection limits while the solvent acetone accumulated in biological treatments through time. Salinity concentrations of 40 g/L or more completely inhibited degradation during the first 6.5 days of incubation with the synthetic hydraulic fracturing fluid even though communities were pre-acclimated to salt. Initially diverse microbial communities became dominated by 16S rRNA sequences affiliated with Pseudomonas and other Pseudomonadaceae after incubation with the synthetic fracturing fluid, taxa which may be involved in acetone production. These data expand our understanding of constraints on the biodegradation potential of organic compounds in hydraulic fracturing fluids under aerobic conditions in the event that they are accidentally released to surface waters and shallow soils. PMID:26037076

  10. Low-temperature MTBE biodegradation in aquifer sediments with a history of low, seasonal ground water temperatures

    USGS Publications Warehouse

    Bradley, P.M.; Landmeyer, J.E.

    2006-01-01

    Sediments from two shallow, methyl tert-butyl ether (MTBE)-contaminated aquifers, with mean ground water temperatures ???10??C, demonstrated significant mineralization of [U-14C] MTBE to 14CO 2 at incubation temperatures as low as 4??C. These results indicate that microbial degradation can continue to contribute to the attenuation of MTBE in ground water under wintertime, low-temperature conditions. ?? 2006 National Ground Water Association.

  11. Physicochemical treatments of anionic surfactants wastewater: Effect on aerobic biodegradability.

    PubMed

    Aloui, Fathi; Kchaou, Sonia; Sayadi, Sami

    2009-05-15

    The effect of different physicochemical treatments on the aerobic biodegradability of an industrial wastewater resulting from a cosmetic industry has been investigated. This industrial wastewater contains 11423 and 3148mgL(-1) of chemical oxygen demand (COD) and anionic surfactants, respectively. The concentration of COD and anionic surfactants were followed throughout the diverse physicochemical treatments and biodegradation experiments. Different pretreatments of this industrial wastewater using chemical flocculation process with lime and aluminium sulphate (alum), and also advanced oxidation process (electro-coagulation (Fe and Al) and electro-Fenton) led to important COD and anionic surfactants removals. The best results were obtained using electro-Fenton process, exceeding 98 and 80% of anionic surfactants and COD removals, respectively. The biological treatment by an isolated strain Citrobacter braakii of the surfactant wastewater, as well as the pretreated wastewater by the various physicochemical processes used in this study showed that the best results were obtained with electro-Fenton pretreated wastewater. The characterization of the treated surfactant wastewater by the integrated process (electro-coagulation or electro-Fenton)-biological showed that it respects Tunisian discharge standards. PMID:18799262

  12. Biodegradability and biodegradation rate of poly(caprolactone)-starch blend and poly(butylene succinate) biodegradable polymer under aerobic and anaerobic environment.

    PubMed

    Cho, H S; Moon, H S; Kim, M; Nam, K; Kim, J Y

    2011-03-01

    The biodegradability and the biodegradation rate of two kinds biodegradable polymers; poly(caprolactone) (PCL)-starch blend and poly(butylene succinate) (PBS), were investigated under both aerobic and anaerobic conditions. PCL-starch blend was easily degraded, with 88% biodegradability in 44 days under aerobic conditions, and showed a biodegradation rate of 0.07 day(-1), whereas the biodegradability of PBS was only 31% in 80 days under the same conditions, with a biodegradation rate of 0.01 day(-1). Anaerobic bacteria degraded well PCL-starch blend (i.e., 83% biodegradability for 139 days); however, its biodegradation rate was relatively slow (6.1 mL CH(4)/g-VS day) compared to that of cellulose (13.5 mL CH(4)/g-VS day), which was used as a reference material. The PBS was barely degraded under anaerobic conditions, with only 2% biodegradability in 100 days. These results were consistent with the visual changes and FE-SEM images of the two biodegradable polymers after the landfill burial test, showing that only PCL-starch blend had various sized pinholes on the surface due to attack by microorganisms. This result may be use in deciding suitable final disposal approaches of different types of biodegradable polymers in the future. PMID:21144726

  13. MTBE IN SITU BIODEGRADATION IN BIONETS USING ISOLITE, PM1, SLOW RELEASING OXYGEN AND AIR IN INDIAN COUNTRY

    EPA Science Inventory

    Methyl tert-Butyl Ether (MTBE), a gasoline additive, is a persistent, foul tasting chemical and more mobile in ground water than BTEX. Our objective was to determine if biologically active in situ Bionets could bioremediate MTBE. Seven Bionets, most containing 3 fractures each,...

  14. Potential waste minimization of trichloroethylene and perchloroethylene via aerobic biodegradation.

    PubMed

    Wang, Jian; Cutright, Teresa J

    2005-01-01

    Trichloroethylene (TCE) and perchloroethylene (PCE) are two of the most frequently detected chlorinated organics found in groundwater. Biodegradation with a new aerobic consortium was used to ascertain the viability of bioremediation for waste minimization applications. After 1 week of treatment, the degradation rate constants, k, were between 0.004 and 0.012 d(-1) for initial concentrations of 54-664 microM TCE. When PCE was used as the sole contaminant, the k values were approximately 0.01 d(-1) regardless of the initial concentration. The addition of 0.2 microM toluene or phenol as an inducer dramatically increased TCE degradation. For instance, at 200 microM TCE the k value when toluene was added (0.03 d(-1)) was 2.2 times higher than without inducers (0.009 d(-1)). The addition of 0.2 microM phenol increased the rate constant by 58%. However, PCE degradation rates were not changed significantly. PMID:15991724

  15. Aerobic biodegradation of iso-butanol and ethanol and their relative effects on BTEX biodegradation in aquifer materials.

    PubMed

    Schaefer, Charles E; Yang, Xiaomin; Pelz, Oliver; Tsao, David T; Streger, Sheryl H; Steffan, Robert J

    2010-11-01

    The aerobic biodegradability of iso-butanol, a new biofuel, and its impact on benzene, toluene, ethylbenzene and xylenes (BTEX) degradation was investigated in aerobic microcosms consisting of groundwater and sediment from a California site with a history of gasoline contamination. To the best of our knowledge this is the first study directly examining the effects of iso-butanol on BTEX degradation. Microcosms that received either low (68 μM) or high (3400 μM) concentrations of iso-butanol showed complete biodegradation of iso-butanol within 7 and 23 d, respectively, of incubation at 15°C under aerobic conditions. A maximum utilization rate coefficient of 2.3±0.1×10⁻⁷ μmol cell⁻¹ h⁻¹ and a half saturation constant of 610±54 μM were regressed from the iso-butanol data. Iso-butanol biodegradation resulted in transient formation of the degradation intermediate products iso-butylaldehyde and iso-butyric acid, and both compounds were subsequently degraded within the timeframe of the experiments. Ethanol was biodegraded more slowly than iso-butanol. Ethanol also exhibited greater adverse impacts on BTEX biodegradation than iso-butanol. Results of the study suggest that iso-butanol added to fuels will be readily biodegraded in the environment under aerobic conditions without the accumulation of major intermediate products (iso-butylaldehyde and iso-butyric acid), and that it will pose less impacts on BTEX biodegradation than ethanol. PMID:20875664

  16. Could petroleum biodegradation be a joint achievement of aerobic and anaerobic microrganisms in deep sea reservoirs?

    PubMed Central

    2011-01-01

    Several studies suggest that petroleum biodegradation can be achieved by either aerobic or anaerobic microorganisms, depending on oxygen input or other electron acceptors and appropriate nutrients. Evidence from in vitro experiments with samples of petroleum formation water and oils from Pampo Field indicate that petroleum biodegradation is more likely to be a joint achievement of both aerobic and anaerobic bacterial consortium, refining our previous observations of aerobic degradation. The aerobic consortium depleted, in decreasing order, hydrocarbons > hopanes > steranes > tricyclic terpanes while the anaerobic consortium depleted hydrocarbons > steranes > hopanes > tricyclic terpanes. The oxygen content of the mixed consortia was measured from time to time revealing alternating periods of microaerobicity (O2 ~0.8 mg.L-1) and of aerobicity (O2~6.0 mg.L-1). In this experiment, the petroleum biodegradation changed from time to time, alternating periods of biodegradation similar to the aerobic process and periods of biodegradation similar to the anaerobic process. The consortia showed preferences for metabolizing hydrocarbons > hopanes > steranes > tricyclic terpanes during a 90-day period, after which this trend changed and steranes were more biodegraded than hopanes. The analysis of aerobic oil degrading microbiota by the 16S rRNA gene clone library detected the presence of Bacillus, Brevibacterium, Mesorhizobium and Achromobacter, and the analysis of the anaerobic oil degrading microbiota using the same technique detected the presence of Bacillus and Acinetobacter (facultative strains). In the mixed consortia Stenotrophomonas, Brevibacterium, Bacillus, Rhizobium, Achromobacter and 5% uncultured bacteria were detected. This is certainly a new contribution to the study of reservoir biodegradation processes, combining two of the more important accepted hypotheses. PMID:22196374

  17. Involvement of Linear Plasmids in Aerobic Biodegradation of Vinyl Chloride

    SciTech Connect

    BRIGMON, ROBINL.

    2004-06-14

    Pseudomonas putida strain AJ and Ochrobactrum strain TD were isolated from hazardous waste sites based on their ability to use vinyl chloride (VC) as a sole source of carbon and energy under aerobic conditions. Strains AJ and TD also use ethene and ethylene oxide as growth substrates. Strain AJ contained a linear megaplasmid (approximately 260 kb) when grown on VC or ethene, but no circular plasmids. While growing on ethylene oxide, the size of the linear plasmid in strain AJ decreased to approximately 100 kb, although its ability to use VC as a substrate was retained. The linear plasmids in strain AJ were cured and its ability to consume VC, ethene, and ethylene oxide was lost following growth on a rich substrate (Luria-Bertani broth) through at least three transfers. Strain TD contained three linear plasmids, ranging in size from approximately 100 kb to 320 kb, when growing on VC or ethene. As with strain AJ, the linear plasmids in strain TD were cured following growth on Luria -Bertani broth and its ability to consume VC and ethene was lost. Further analysis of these linear plasmids may help reveal the pathway for VC biodegradation in strains AJ and TD and explain why this process occurs at many but not all sites where groundwater is contaminated with chloroethenes. Metabolism of VC and ethene by strains AJ and TD is initiated by an alkene monooxygenase. Their yields during growth on VC (0.15-0.20 mg total suspended solids per mg VC) are similar to the yields reported for other isolates i.e., Mycobacterium sp., Nocardioides sp., and Pseudomonas sp.

  18. Kinetics and thermodynamics of biodegradation of hydrolyzed polyacrylamide under anaerobic and aerobic conditions.

    PubMed

    Zhao, Lanmei; Bao, Mutai; Yan, Miao; Lu, Jinren

    2016-09-01

    Kinetics and thermodynamics of hydrolyzed polyacrylamide (HPAM) biodegradation in anaerobic and aerobic activated sludge biochemical treatment systems were explored to determine the maximum rate and feasibility of HPAM biodegradation. The optimal nutrient proportions for HPAM biodegradation were determined to be 0.08g·L(-1) C6H12O6, 1.00g·L(-1) NH4Cl, 0.36g·L(-1) NaH2PO4 and 3.00g·L(-1) K2HPO4 using response surface methodology (RSM). Based on the kinetics, the maximum HPAM biodegradation rates were 16.43385mg·L(-1)·d(-1) and 2.463mg·L(-1)·d(-1) in aerobic and anaerobic conditions, respectively. The activation energy (Ea) of the aerobic biodegradation was 48.9897kJ·mol(-1). Entropy changes (ΔS) of biochemical treatment system decreased from 216.21J·K(-1) to 2.39J·K(-1). Thermodynamic windows of opportunity for HPAM biodegradation were drawn. And it demonstrated HPAM was biodegraded into acetic acid and CO2 under laboratory conditions. Growth-process equations for functional bacteria anaerobically grown on polyacrylic acid were constructed and it confirmed electron equivalence between substrate and product. PMID:27235971

  19. Aerobic biodegradation process of petroleum and pathway of main compounds in water flooding well of Dagang oil field.

    PubMed

    Cai, Minmin; Yao, Jun; Yang, Huaijun; Wang, Ruixia; Masakorala, Kanaji

    2013-09-01

    Aerobic biodegradation of crude oil and its pathways were investigated via in vitro culture and GC-MS analysis in water flooding wells of Dagang oil field. The in vitro aerobic culture lasted 90 days when 99.0% of n-alkanes and 43.03-99.9% of PAHs were degraded and the biomarkers and their ratios were changed. The spectra of components in the residual oil showed the similar biodegradation between aerobic process of 90 days and degradation in reservoir which may last for some millions years, and the potential of serious aerobic biodegradation of petroleum in reservoir. 24 Metabolites compounds were separated and identified from aerobic culture, including fatty acid, naphthenic acid, aromatic carboxylic acid, unsaturated acid, alcohols, ketones and aldehydes. The pathways of alkanes and aromatics were proposed, which suggests that oxidation of hydrocarbon to organic acid is an important process in the aerobic biodegradation of petroleum. PMID:23867530

  20. Aerobic biodegradation of the brominated flame retardants, dibromoneopentyl glycol and tribromoneopentyl alcohol.

    PubMed

    Segev, Osnat; Meusel, Wolfram; Friedenberger, Melanie; Brenner, Asher; Kushmaro, Ariel

    2009-09-01

    Halogenated organic compounds constitute one of the largest and most diverse groups of chemicals in the environment. Many of these compounds are toxic, persistent and, as a result of their often limited biodegradability, tend to bioaccumulate in the environment. Dibromoneopentyl glycol (DBNPG) and tribromoneopentyl alcohol (TBNPA) are brominated flame retardants commonly used as additives during the manufacture of plastic polymers and as chemical intermediates in the synthesis of other flame retardants. Both are classified as not readily biodegradable. In this paper, we demonstrate the biodegradation of both DBNPG and TBNPA by a common bacterial consortium under aerobic conditions in enrichment cultures containing yeast extract. DBNPG and TBNPA biodegradation is accompanied by a release of bromide into the medium, due to a biological debromination reaction. Molecular analysis of the clone library PCR amplified 16S rRNA gene was used to characterize the bacterial consortium involved in the biodegradation. PMID:19205903

  1. AN ENRICHMENT CULTURE THAT DEGRADES MTBE UNDER ANAEROBIC CONDITIONS

    EPA Science Inventory

    Biodegradation of MTBE in ground water may be a significant factor helping to reduce MTBE contamination from gasoline spills. Previously, decreases in MTBE concentrations in wells at release sites were thought to be due exclusively to dispersion and dilution. Researchers have i...

  2. Aerobic Biodegradation Kinetics And Mineralization Of Six Petrodiesel/Soybean-Biodiesel Blends

    EPA Science Inventory

    The aerobic biodegradation kinetics and mineralization of six petrodiesel/soybean-biodiesel blends (B0, B20, B40, B60, B80, and B100), where B100 is 100% biodiesel, were investigated by acclimated cultures. The fatty acid methyl esters (FAMEs) of biodiesel were found to undergo ...

  3. BIODEGRADATION KINETICS AND TOXICITY OF VEGETABLE OIL TRIACYLGLYCEROLS UNDER AEROBIC CONDITIONS

    EPA Science Inventory

    The aerobic biodegradation of five triacylglycerols (TAGs), three liquids [triolein (OOO), trilinolein (LLL), and trilinolenin (LnLnLn)] and two solids [tripalmitin (PPP) and tristearin (SSS)] was studied in water. Respirometry tests were designed and conducted to determine the b...

  4. AEROBIC SOIL MICROCOSMS FOR LONG-TERM BIODEGRADATION OF HYDROCARBON VAPORS

    EPA Science Inventory

    The aims of this research project included the development of laboratory protocols for the preparation of aerobic soil microcosms using aseptic field soil samples, and for the gas chromatographic analysis of hydrocarbon vapor biodegradation based on vapor samples obtained from th...

  5. Biodegradation of 14C-dicofol in wastewater aerobic treatment and sludge anaerobic biodigestion.

    PubMed

    Oliveira, Jaime L da M; Silva, Denise P; Martins, Edir M; Langenbach, Tomaz; Dezotti, Marcia

    2012-01-01

    Organic micropollutants are often found in domestic and industrial effluents. Thus, it is important to learn their fate, the metabolites generated and their sorption during biological treatment processes. This work investigated the biodegradation of 14C-dicofol organochloride during wastewater aerobic treatment and sludge anaerobic biodigestion. The performance of these processes was evaluated by physical-chemical parameters. Radioactivity levels were monitored in both treatments, and residues of dicofol (DCF) and dichlorobenzophenone (DBP) were quantified by HPLC/UV. The efficiency of the aerobic and anaerobic processes was slightly reduced in the presence of DCF and DBP. After aerobic treatment, only 0.1% of DCF was mineralized, and 57% of radioactivity remained sorbed on biological sludge as DBP. After 18 days of anaerobiosis, only 3% of DCF and 5% of DBP were detected in the sludge. However, 70% of radioactivity remained in the sludge, probably as other metabolites. Dicofol was biodegraded in the investigated process, but not mineralized. PMID:22629645

  6. COMPARISON OF FIELD AEROBIC BIODEGRADATION RATES TO LABORATORY

    EPA Science Inventory

    It is common to use bioventing as a polishing step for soil vapor extraction. It was originally planned to use soil vapor extraction and bioventing at a former landfill site in Delaware but laboratory scale biodegradation studies indicated that most of the volatile organic compou...

  7. AEROBIC BIODEGRADABILITY AND TOXICITY OF NON-PETROLEUM OILS.

    EPA Science Inventory

    Vegetable oil spills are a widely known phenomenon, but are the least understood. These spills can be as devastating to the environment as petroleum oil spills. Previous laboratory research results have indicated that as vegetable oils degrade aerobically, the aqueous solutions b...

  8. Biodegradation of tributyl phosphate, an organosphate triester, by aerobic granular biofilms.

    PubMed

    Nancharaiah, Y V; Kiran Kumar Reddy, G; Krishna Mohan, T V; Venugopalan, V P

    2015-01-01

    Tributyl phosphate (TBP) is commercially used in large volumes for reprocessing of spent nuclear fuel. TBP is a very stable compound and persistent in natural environments and it is not removed in conventional wastewater treatment plants. In this study, cultivation of aerobic granular biofilms in a sequencing batch reactor was investigated for efficient biodegradation of TBP. Enrichment of TBP-degrading strains resulted in efficient degradation of TBP as sole carbon or along with acetate. Complete biodegradation of 2mM of TBP was achieved within 5h with a degradation rate of 0.4 μmol mL(-1) h(-1). TBP biodegradation was accompanied by release of inorganic phosphate in stoichiometric amounts. n-Butanol, hydrolysed product of TBP was rapidly biodegraded. But, dibutyl phosphate, a putative intermediate of TBP degradation was only partially degraded pointing to an alternative degradation pathway. Phosphatase activity was 22- and 7.5-fold higher in TBP-degrading biofilms as compared to bioflocs and acetate-fed aerobic granules. Community analysis by terminal restriction length polymorphism revealed presence of 30 different bacterial strains. Seven bacterial stains, including Sphingobium sp. a known TBP degrader were isolated. The results show that aerobic granular biofilms are promising for treatment of TBP-bearing wastes or ex situ bioremediation of TBP-contaminated sites. PMID:25464313

  9. Aerobic granular sludge mediated biodegradation of an organophosphorous ester, dibutyl phosphite.

    PubMed

    Kiran Kumar Reddy, G; Nancharaiah, Yarlagadda Venkata; Venugopalan, Vayalam Purath

    2014-10-01

    Dibutyl phosphite, an organophosphorous compound, finds applications in different chemical industries and processes. Here, we report an efficient approach of biodegradation to be eventually used in bioremediation of dibutyl phosphite. Aerobic granules capable of dibutyl phosphite biodegradation were cultivated in a sequencing batch reactor (SBR). The SBR was operated with a 24-h cycle by feeding with dibutyl phosphite as a cosubstrate along with acetate. During the course of the SBR operation, aerobic granules of 0.9 ± 0.3 mm size were developed. Complete biodegradation of 1.4, 2 and 3 mM of dibutyl phosphite was achieved in 4, 5 and 8 h, respectively, accompanied by stoichiometric release of phosphite (H3 PO3). Phosphatase activity in the dibutyl phosphite-degrading granular biomass was 3- and 1.5-fold higher as compared to the activated sludge (seed biomass) and acetate-fed aerobic granules, respectively, indicating involvement in the hydrolysis of dibutyl phosphite. Microbial community analysis by t-RFLP showed the presence of 12 different bacterial types. Two bacterial strains capable of growth on dibutyl phosphite as sole carbon source were isolated and characterized as Acidovorax sp. and Sphingobium sp. The results show that aerobic microbial granules based process is suitable for the treatment of dibutyl phosphite contaminated water. PMID:25135363

  10. ANAEROBIC/AEROBIC BIODEGRADATION OF PENTACHLOROPHENOL USING GAC FLUIDIXED BED REACTORS: OPTIMIZATION OF THE EMPTY BED CONTACT TIME

    EPA Science Inventory

    An integrated reactor system has been developed to remediate pentachlorophenol (PCP) containing wastes using sequential anaerobic and aerobic biodegradation. Anaerobically, PCP was degraded to approximately equimolar concentrations (>99%) of chlorophenol (CP) in a granular activa...

  11. Compound-Specific Carbon and Hydrogen Isotope Analysis - Field Evidence of MTBE Bioremediation

    NASA Astrophysics Data System (ADS)

    Kuder, T.; Kolhatkar, R. V.; Philp, P.; Wilson, J. T.; Landmeyer, J. E.; Allen, J.

    2002-12-01

    Compound-specific stable isotope analysis allows opportunity to determine the isotopic ratios of individual contaminants. The technique has been applied to confirm biodegradation in studies of chlorinated solvents and recently BTEX, MTBE and TBA. Chemical reactions (including bio- and inorganic degradation) tend to favor molecules with the lighter isotopic species (e.g., 12C, 1H), resulting with enrichment of the unreacted substrate in the heavier isotopic species (13C, D), referred to as kinetic isotopic fractionation, so that the extent of fractionation may be used as a proxy for biodegradation. Processes such as volatilization, sorption etc., result in minimal degree of fractionation and do not interfere with the isotopic signal due to biodegradation. The results presented here show the first successful applications of compound-specific isotope analysis to understanding MTBE biodegradation in the field, at both aerobic and anaerobic sites. Observed fractionations suggest that two different biodegradation pathways may be involved. At a number of anaerobic locations major fractionation effects were observed for both C and H; enrichment factors Ÿnfor both elements were approaching or exceeding -10. A laboratory microcosm study using an enrichment culture yielded similar results (C data only). A characteristic feature of these sites was the presence of high concentrations of TBA. Conversely, at a number of sites, the C composition remained stable with little fractionation and stayed within the analytical precision range or changed minimally, while H displayed significant fractionation in excess of 60 per mil. Moderate agreement of the data with Rayleigh fractionation model was observed, suggesting that biodegradation effect was distorted by variability at the source or the plume was not homogeneous. The enrichment factor calculated for these data is similar to the one Ÿnpublished for aerobic microcosm of MTBE-degrading culture from Vandenberg AFB by Gray et al

  12. Aerobic and anaerobic PCB biodegradation in the environment

    SciTech Connect

    Abramowicz, D.A.

    1995-06-01

    Studies have identified two distinct biological processes capable of biotransforming polychlorinated biphenyls (PCBs): aerobic oxidative processes and anaerobic reductive processes. It is now known that these two complementary activities are occurring naturally in the environment. Anaerobic PCB dechlorination, responsible for the conversion of highly chlorinated PCBs to lightly chlorinated ortho-enriched congeners, has been documented extensively in the Hudson River and has been observed at many other sites throughout the world. The products from this anaerobic process are readily degradable by a wide range of aerobic bacteria, and it has now been shown that this process is occurring in surficial sediments in the Hudson River. The widespread anaerobic dechlorination of PCBs that has been observed in many river and marine sediments results in reduction of both the potential risk from and potential exposure to PCBs. The reductions in potential risk include reduced dioxin like toxicity and reduced carcinogenicity. The reduced PCB exposure realized upon dechlorination is manifested by reduced bioaccumulation in the food chain and by the increased anaerobic degradability of these products. 27 refs., 1 fig., 1 tab.

  13. A comparison of the effects of two methods of acclimation of aerobic biodegradability

    SciTech Connect

    Watson, H.M. . Environmental Sciences Section)

    1993-11-01

    The acclimation or adaptation of microorganisms to organic chemicals is an important factor influencing both the rate and the extent of biodegradation. In this study two acclimation procedures were evaluated in terms of their effectiveness in enhancing biodegradation, their relative ease of use in the laboratory, and the implications for biodegradability testing. In the single-flask procedure, microorganisms were acclimated for 2 to 7 d in a single acclimation flask at constant or increasing concentrations of the test chemical without transfer of microorganisms. In the second procedure, the enrichment procedure, microorganisms were acclimated in a series of flasks over a 21-d period by making adaptive transfers to increasing concentrations of the test chemical. Acclimated microorganisms from each procedure were used as the source of inoculum for subsequent biodegradation tests in which carbon dioxide evolution was measured. Six chemicals were tested: quinoline, p-nitrophenol, N-methylaniline, N,N-dimethylaniline, acrylonitrile, and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate. Microorganisms acclimated in the single-flask procedure were much more effective than those acclimated in the enrichment procedure in degrading the test chemicals. The single-flask procedure is more convenient to use, and it permits monitoring of the time needed for acclimation. The results from these studies have implications for the methodology used in biodegradation test systems and suggest caution before adopting a multiple-flask, enrichment acclimation procedure before the performance of standardized tests for aerobic biodegradability.

  14. Enhancement of aerobic biodegradability potential of municipal waste activated sludge by ultrasonic aided bacterial disintegration.

    PubMed

    Kavitha, S; Jessin Brindha, G M; Sally Gloriana, A; Rajashankar, K; Yeom, Ick Tae; Rajesh Banu, J

    2016-01-01

    An investigation was performed to study the influence of ultrasonic aided bacterial disintegration on the aerobic degradability of sludge. In first phase of the study, effective floc disruption was achieved at an ultrasonic specific energy input of 2.45kJ/kg TS with 44.5mg/L of Extracellular Polymeric Substance (EPS) release including 0.035U/mL and 0.025U/mL protease and amylase activity respectively. In second phase, experimental outcomes revealed bacterial disintegration of floc disrupted-sludge showing a maximum solubilization of about 23% and was observed to be superior to bacterially disintegrated (11%) and control (6%), respectively. The result of aerobic biodegradability of ultrasonic aided bacterially pretreated sludge showed volatile solids (VS) degradation of about 40.2%. The kinetic study of aerobic biodegradability through non linear regression modelling reveals that floc disrupted sludge showed better biodegradability with decay constant of about 0.19d(-1) relatively higher than the control (0.14d(-1)) and bacterially disintegrated (0.17d(-1)) sludges. PMID:26479431

  15. Hydrogen Isotope Fractionation As a Tool to Identify Aerobic and Anaerobic PAH Biodegradation.

    PubMed

    Kümmel, Steffen; Starke, Robert; Chen, Gao; Musat, Florin; Richnow, Hans H; Vogt, Carsten

    2016-03-15

    Aerobic and anaerobic polycyclic aromatic hydrocarbon (PAH) biodegradation was characterized by compound specific stable isotope analysis (CSIA) of the carbon and hydrogen isotope effects of the enzymatic reactions initiating specific degradation pathways, using naphthalene and 2-methylnaphtalene as model compounds. Aerobic activation of naphthalene and 2-methylnaphthalene by Pseudomonas putida NCIB 9816 and Pseudomonas fluorescens ATCC 17483 containing naphthalene dioxygenases was associated with moderate carbon isotope fractionation (εC = -0.8 ± 0.1‰ to -1.6 ± 0.2‰). In contrast, anaerobic activation of naphthalene by a carboxylation-like mechanism by strain NaphS6 was linked to negligible carbon isotope fractionation (εC = -0.2 ± 0.2‰ to -0.4 ± 0.3‰). Notably, anaerobic activation of naphthalene by strain NaphS6 exhibited a normal hydrogen isotope fractionation (εH = -11 ± 2‰ to -47 ± 4‰), whereas an inverse hydrogen isotope fractionation was observed for the aerobic strains (εH = +15 ± 2‰ to +71 ± 6‰). Additionally, isotope fractionation of NaphS6 was determined in an overlaying hydrophobic carrier phase, resulting in more reliable enrichment factors compared to immobilizing the PAHs on the bottle walls without carrier phase. The observed differences especially in hydrogen fractionation might be used to differentiate between aerobic and anaerobic naphthalene and 2-methylnaphthalene biodegradation pathways at PAH-contaminated field sites. PMID:26855125

  16. Biodegradation of o-nitrophenol by aerobic granules with glucose as co-substrate.

    PubMed

    Basheer, Farrukh; Isa, M H; Farooqi, I H

    2012-01-01

    Aerobic granules to treat wastewater containing o-nitrophenol were successfully developed in a sequencing batch reactor (SBR) using activated sludge as inoculum. Stable aerobic granules were obtained with a clearly defined shape and diameters ranging from 2 to 6 mm after 122 days of operation. The integrity coefficient (IC) and granules density was found to be 98% and 1,054 kg m(-3) respectively. After development of aerobic granules, o-nitrophenols were successfully degraded to an efficiency of 78% at a concentration of 70 mg L(-1). GC-MS study revealed that the biodegradation of o-nitrophenol occurred via catechol via nitrobenzene pathway. Specific o-nitrophenol biodegradation rates followed the Haldane model and the associated kinetic parameters were found as follows: V(max) = 3.96 g o-nitrophenol g(-1)VSS(-1)d(-1), K(s) = 198.12 mg L(-1), and K(i) = 31.16 mg L(-1). The aerobic granules proved to be a feasible and effective way to degrade o-nitrophenol containing wastewater. PMID:22643407

  17. Design and construction of a medium-scale automated direct measurement respirometric system to assess aerobic biodegradation of polymers

    NASA Astrophysics Data System (ADS)

    Castro Aguirre, Edgar

    A medium-scale automated direct measurement respirometric (DMR) system was designed and built to assess the aerobic biodegradation of up to 30 materials in triplicate simultaneously. Likewise, a computer application was developed for rapid analysis of the data generated. The developed DMR system was able to simulate different testing conditions by varying temperature and relative humidity, which are the major exposure conditions affecting biodegradation. Two complete tests for determining the aerobic biodegradation of polymers under composting conditions were performed to show the efficacy and efficiency of both the DMR system and the DMR data analyzer. In both cases, cellulose reached 70% mineralization at 139 and 45 days. The difference in time for cellulose to reach 70% mineralization was attributed to the composition of the compost and water availability, which highly affect the biodegradation rate. Finally, among the tested materials, at least 60% of the organic carbon content of the biodegradable polymers was converted into carbon dioxide by the end of the test.

  18. Effects of Rate-Limited Mass Transfer on Modeling Vapor Intrusion with Aerobic Biodegradation.

    PubMed

    Chen, Yiming; Hou, Deyi; Lu, Chunhui; Spain, Jim C; Luo, Jian

    2016-09-01

    Most of the models for simulating vapor intrusion accept the local equilibrium assumption for multiphase concentration distributions, that is, concentrations in solid, liquid and vapor phases are in equilibrium. For simulating vapor transport with aerobic biodegradation controlled by counter-diffusion processes, the local equilibrium assumption combined with dual-Monod kinetics and biomass decay may yield near-instantaneous behavior at steady state. The present research investigates how predicted concentration profiles and fluxes change as interphase mass transfer resistances are increased for vapor intrusion with aerobic biodegradation. Our modeling results indicate that the attenuation coefficients for cases with and without mass transfer limitations can be significantly different by orders of magnitude. Rate-limited mass transfer may lead to larger overlaps of contaminant vapor and oxygen concentrations, which cannot be simulated by instantaneous reaction models with local equilibrium mass transfer. In addition, the contaminant flux with rate-limited mass transfer is much smaller than that with local equilibrium mass transfer, indicating that local equilibrium mass transfer assumption may significantly overestimate the biodegradation rate and capacity for mitigating vapor intrusion through the unsaturated zone. Our results indicate a strong research need for field tests to examine the validity of local equilibrium mass transfer, a widely accepted assumption in modeling vapor intrusion. PMID:27486832

  19. A rapid in situ respiration test for measuring aerobic biodegradation rates of hydrocarbons in soil.

    PubMed

    Hinchee, R E; Ong, S K

    1992-10-01

    An in situ test method to measure the aerobic biodegradation rates of hydrocarbons in contaminated soil is presented. The test method provides an initial assessment of bioventing as a remediation technology for hydrocarbon-contaminated soil. The in situ respiration test consists of ventilating the contaminated soil of the unsaturated zone with air and periodically monitoring the depletion of oxygen (O2) and production of carbon dioxide (CO2) over time after the air is turned off. The test is simple to implement and generally takes about four to five days to complete. The test was applied at eight hydrocarbon-contaminated sites of different geological and climatic conditions. These sites were contaminated with petroleum products or petroleum fuels, except for two sites where the contaminants were primarily polycyclic aromatic hydrocarbons. Oxygen utilization rates for the eight sites ranged from 0.02 to 0.99 percent O2/hour. Estimated biodegradation rates ranged from 0.4 to 19 mg/kg of soil/day. These rates were similar to the biodegradation rates obtained from field and pilot studies using mass balance methods. Estimated biodegradation rates based on O2 utilization were generally more reliable (especially for alkaline soils) than rates based on CO2 production. CO2 produced from microbial respiration was probably converted to carbonate under alkaline conditions. PMID:1418936

  20. Simulating the effect of aerobic biodegradation on soil vapor intrusion into buildings: influence of degradation rate, source concentration, and depth.

    PubMed

    Abreu, Lilian D V; Johnson, Paul C

    2006-04-01

    Steady-state vapor intrusion scenarios involving aerobically biodegradable chemicals are studied using a three-dimensional multicomponent numerical model. In these scenarios, sources of aerobically biodegradable chemical vapors are placed at depths of 1-14 m beneath a 10 m x 10 m basement or slab-on-grade construction building, and the simultaneous transport and reaction of hydrocarbon and oxygen vapors are simulated. The results are presented as Johnson and Ettinger attenuation factors alpha (predicted indoor air hydrocarbon concentration/source vapor concentration), and normalized contour plots of hydrocarbon and oxygen concentrations. In addition to varying the vapor source depth, the effects of source concentration (2-200 mg chemical/L vapor) and oxygen-limited first-order reaction rates (0.018-1.8 h(-1)) are studied. Hydrocarbon inputs were specific to benzene, although the relevant properties are similar to those for a range of hydrocarbons of interest. Overall, the results suggest that aerobic biodegradation could play a significant role in reducing vapor intrusion into buildings (decreased alpha-values) relative to the no-biodegradation case, with the significance of aerobic biodegradation increasing with increasing vapor source depth, decreasing vapor source concentration, and increasing first-order biodegradation rate. In contrast to the no-biodegradation case, differences in foundation construction can be significant in some settings. The significance of aerobic biodegradation is directly related to the extent to which oxygen is capable of migrating beneath the foundation. For example, in the case of a basement scenario with a 200 mg/L vapor source located at 3 m bgs, oxygen is consumed before it can migrate beneath the foundation, so the attenuation factors for simulations with and without aerobic biodegradation are similar for all first-order rates studied. For the case of a 2 mg/L vapor source located at 8 m bgs, the oxygen is widely distributed

  1. Fate and Tranport of MTBE in Clay-Rich Materials

    NASA Astrophysics Data System (ADS)

    lenczewski, m e

    2001-12-01

    A recent report by the U.S. Geological Survey identified methyl tert-butyl ether (MTBE), a constituent of reformulated gasoline, as the most common contaminant of urban aquifers in the United States. MTBE has been released into groundwater supplies by leaking underground fuel tanks. In Illinois, it has been found in 26 of the 1,800 public water supplies and although detection was intermittent, levels were high enough to be offensive to users in some Illinois communities. MTBE is also being used in Mexico to solve the problem of air quality; however, it has the potential to harm the drinking water quality in the process. Early research on MTBE considered it resistant to biodegradation and unable to adsorb to soils and sediments. However, recent evidence indicates that biodegradation does occur under certain conditions and that sorption can occur to organic materials. This research project will investigate the biodegradation of MTBE and its sorption to the clay-rich glacial till found in northern Illinois and lacustrine clays found in the Chalco Basin, Mexico City, Mexico whose interaction with MTBE has not previously been studied. The principal hypothesis of this research is that the microorganisms and environmental factors in clay-rich materials will increase the biodegradation and sorption of MTBE as compared to sandy materials. The experiments will simulate a spill of MTBE or downgradient from a gasoline spill. Microcosms and batch isotherm experiments will be used to demonstrate the potential for biodegradation and sorption in these materials; however, laboratory results are not considered reliable estimates of actual field sorption and biodegradation rates. Therefore long-term column experiments will also be conducted in which large sample volumes of material that simulate the heterogeneities naturally observed in the environment. This research will increase understanding of the biodegradation and sorption of MTBE and lay the necessary groundwork to implement

  2. Biodegradation and detoxification of textile azo dyes by bacterial consortium under sequential microaerophilic/aerobic processes.

    PubMed

    Lade, Harshad; Kadam, Avinash; Paul, Diby; Govindwar, Sanjay

    2015-01-01

    Release of textile azo dyes to the environment is an issue of health concern while the use of microorganisms has proved to be the best option for remediation. Thus, in the present study, a bacterial consortium consisting of Providencia rettgeri strain HSL1 and Pseudomonas sp. SUK1 has been investigated for degradation and detoxification of structurally different azo dyes. The consortium showed 98-99 % decolorization of all the selected azo dyes viz. Reactive Black 5 (RB 5), Reactive Orange 16 (RO 16), Disperse Red 78 (DR 78) and Direct Red 81 (DR 81) within 12 to 30 h at 100 mg L(-1) concentration at 30 ± 0.2 °C under microaerophilic, sequential aerobic/microaerophilic and microaerophilic/aerobic processes. However, decolorization under microaerophilic conditions viz. RB 5 (0.26 mM), RO 16 (0.18 mM), DR 78 (0.20 mM) and DR 81 (0.23 mM) and sequential aerobic/microaerophilic processes viz. RB 5 (0.08 mM), RO 16 (0.06 mM), DR 78 (0.07 mM) and DR 81 (0.09 mM) resulted into the formation of aromatic amines. In distinction, sequential microaerophilic/ aerobic process doesn't show the formation of amines. Additionally, 62-72 % reduction in total organic carbon content was observed in all the dyes decolorized broths under sequential microaerophilic/aerobic processes suggesting the efficacy of method in mineralization of dyes. Notable induction within the levels of azoreductase and NADH-DCIP reductase (97 and 229 % for RB 5, 55 and 160 % for RO 16, 63 and 196 % for DR 78, 108 and 258 % for DR 81) observed under sequential microaerophilic/aerobic processes suggested their critical involvements in the initial breakdown of azo bonds, whereas, a slight increase in the levels of laccase and veratryl alcohol oxidase confirmed subsequent oxidation of formed amines. Also, the acute toxicity assay with Daphnia magna revealed the nontoxic nature of the dye-degraded metabolites under sequential microaerophilic/aerobic processes. As biodegradation under sequential microaerophilic/aerobic

  3. Biodegradation and detoxification of textile azo dyes by bacterial consortium under sequential microaerophilic/aerobic processes

    PubMed Central

    Lade, Harshad; Kadam, Avinash; Paul, Diby; Govindwar, Sanjay

    2015-01-01

    Release of textile azo dyes to the environment is an issue of health concern while the use of microorganisms has proved to be the best option for remediation. Thus, in the present study, a bacterial consortium consisting of Providencia rettgeri strain HSL1 and Pseudomonas sp. SUK1 has been investigated for degradation and detoxification of structurally different azo dyes. The consortium showed 98-99 % decolorization of all the selected azo dyes viz. Reactive Black 5 (RB 5), Reactive Orange 16 (RO 16), Disperse Red 78 (DR 78) and Direct Red 81 (DR 81) within 12 to 30 h at 100 mg L-1 concentration at 30 ± 0.2 °C under microaerophilic, sequential aerobic/microaerophilic and microaerophilic/aerobic processes. However, decolorization under microaerophilic conditions viz. RB 5 (0.26 mM), RO 16 (0.18 mM), DR 78 (0.20 mM) and DR 81 (0.23 mM) and sequential aerobic/microaerophilic processes viz. RB 5 (0.08 mM), RO 16 (0.06 mM), DR 78 (0.07 mM) and DR 81 (0.09 mM) resulted into the formation of aromatic amines. In distinction, sequential microaerophilic/ aerobic process doesn’t show the formation of amines. Additionally, 62-72 % reduction in total organic carbon content was observed in all the dyes decolorized broths under sequential microaerophilic/aerobic processes suggesting the efficacy of method in mineralization of dyes. Notable induction within the levels of azoreductase and NADH-DCIP reductase (97 and 229 % for RB 5, 55 and 160 % for RO 16, 63 and 196 % for DR 78, 108 and 258 % for DR 81) observed under sequential microaerophilic/aerobic processes suggested their critical involvements in the initial breakdown of azo bonds, whereas, a slight increase in the levels of laccase and veratryl alcohol oxidase confirmed subsequent oxidation of formed amines. Also, the acute toxicity assay with Daphnia magna revealed the nontoxic nature of the dye-degraded metabolites under sequential microaerophilic/aerobic processes. As biodegradation under sequential microaerophilic/aerobic

  4. Biodegradation of Free Phytol by Bacterial Communities Isolated from Marine Sediments under Aerobic and Denitrifying Conditions

    PubMed Central

    Rontani, Jean-François; Bonin, Patricia C.; Volkman, John K.

    1999-01-01

    Biodegradation of (E)-phytol [3,7,11,15-tetramethylhexadec-2(E)-en-1-ol] by two bacterial communities isolated from recent marine sediments under aerobic and denitrifying conditions was studied at 20°C. This isoprenoid alcohol is metabolized efficiently by these two bacterial communities via 6,10,14-trimethylpentadecan-2-one and (E)-phytenic acid. The first step in both aerobic and anaerobic bacterial degradation of (E)-phytol involves the transient production of (E)-phytenal, which in turn can be abiotically converted to 6,10,14-trimethylpentadecan-2-one. Most of the isoprenoid metabolites identified in vitro could be detected in a fresh sediment core collected at the same site as the sediments used for the incubations. Since (E)-phytenal is less sensitive to abiotic degradation at the temperature of the sediments (15°C), the major part of (E)-phytol appeared to be biodegraded in situ via (E)-phytenic acid. (Z)- and (E)-phytenic acids are present in particularly large quantities in the upper section of the core, and their concentrations quickly decrease with depth in the core. This degradation (which takes place without significant production of phytanic acid) is attributed to the involvement of alternating β-decarboxymethylation and β-oxidation reaction sequences induced by denitrifiers. Despite the low nitrate concentration of marine sediments, denitrifying bacteria seem to play a significant role in the mineralization of (E)-phytol. PMID:10584007

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

    USGS Publications Warehouse

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

    1991-01-01

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

  6. Simultaneous biodegradation of carbon tetrachloride and trichloroethylene in a coupled anaerobic/aerobic biobarrier.

    PubMed

    Kwon, Kiwook; Shim, Hojae; Bae, Wookeun; Oh, Juhyun; Bae, Jisu

    2016-08-01

    Simultaneous biodegradation of carbon tetrachloride (CT) and trichloroethylene (TCE) in a biobarrier with polyethylene glycol (PEG) carriers was studied. Toluene/methanol and hydrogen peroxide (H2O2) were used as electron donors and an electron acceptor source, respectively, in order to develop a biologically active zone. The average removal efficiencies for TCE and toluene were over 99.3%, leaving the respective residual concentrations of ∼12 and ∼57μg/L, which are below or close to the groundwater quality standards. The removal efficiency for CT was ∼98.1%, with its residual concentration (65.8μg/L) slightly over the standards. TCE was aerobically cometabolized with toluene as substrate while CT was anaerobically dechlorinated in the presence of electron donors, with the respective stoichiometric amount of chloride released. The oxygen supply at equivalent to 50% chemical oxygen demand of the injected electron donors supported successful toluene oxidation and also allowed local anaerobic environments for CT reduction. The originally augmented (immobilized in PEG carriers) aerobic microbes were gradually outcompeted in obtaining substrate and oxygen. Instead, newly developed biofilms originated from indigenous microbes in soil adapted to the coupled anaerobic/aerobic environment in the carrier for the simultaneous and almost complete removal of CT, TCE, and toluene. The declined removal rates when temperature fell from 28 to 18°C were recovered by doubling the retention time (7.2 days). PMID:27054665

  7. Estimation of rates of aerobic hydrocarbon biodegradation by simulation of gas transport in the unsaturated zone

    USGS Publications Warehouse

    Lahvis, M.A.; Baehr, A.L.

    1996-01-01

    The distribution of oxygen and carbon dioxide gases in the unsaturated zone provides a geochemical signature of aerobic hydrocarbon degradation at petroleum product spill sites. The fluxes of these gases are proportional to the rate of aerobic biodegradation and are quantified by calibrating a mathematical transport model to the oxygen and carbon dioxide gas concentration data. Reaction stoichiometry is assumed to convert the gas fluxes to a corresponding rate of hydrocarbon degradation. The method is applied at a gasoline spill site in Galloway Township, New Jersey, to determine the rate of aerobic degradation of hydrocarbons associated with passive and bioventing remediation field experiments. At the site, microbial degradation of hydrocarbons near the water table limits the migration of hydrocarbon solutes in groundwater and prevents hydrocarbon volatilization into the unsaturated zone. In the passive remediation experiment a site-wide degradation rate estimate of 34,400 g yr-1 (11.7 gal. yr-1) of hydrocarbon was obtained by model calibration to carbon dioxide gas concentration data collected in December 1989. In the bioventing experiment, degradation rate estimates of 46.0 and 47.9 g m-2 yr-1 (1.45 x 10-3 and 1.51 x 10-3 gal. ft.-2 yr-1) of hydrocarbon were obtained by model calibration to oxygen and carbon dioxide gas concentration data, respectively. Method application was successful in quantifying the significance of a naturally occurring process that can effectively contribute to plume stabilization.

  8. Aerobic biodegradation of sludge with high hydrocarbon content generated by a Mexican natural gas processing facility.

    PubMed

    Roldán-Carrillo, T; Castorena-Cortés, G; Zapata-Peñasco, I; Reyes-Avila, J; Olguín-Lora, P

    2012-03-01

    The biodegradation of oil sludge from Mexican sour gas and petrochemical facilities contaminated with a high content of hydrocarbons, 334.7 ± 7.0 g kg(-1) dry matter (dm), was evaluated. Studies in microcosm systems were carried out in order to determine the capacity of the native microbiota in the sludge to reduce hydrocarbon levels under aerobic conditions. Different carbon/nitrogen/phosphorous (C/N/P) nutrient ratios were tested. The systems were incubated at 30 °C and shaken at 100 rpm. Hydrocarbon removals from 32 to 51% were achieved in the assays after 30 days of incubation. The best assay had C/N/P ratio of 100/1.74/0.5. The results of the Microtox(®) and Ames tests indicated that the original sludge was highly toxic and mutagenic, whereas the best assay gave a final product that did not show toxicity or mutagenicity. PMID:21600691

  9. Quantification of aerobic biodegradation and volatilization rates of gasoline hydrocarbons near the water table under natural attenuation conditions

    USGS Publications Warehouse

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

    1999-01-01

    Aerobic biodegradation and volatilization near the water table constitute a coupled pathway that contributes significantly to the natural attenuation of hydrocarbons at gasoline spill sites. Rates of hydrocarbon biodegradation and volatilization were quantified by analyzing vapor transport in the unsaturated zone at a gasoline spill site in Beaufort, South Carolina. Aerobic biodegradation rates decreased with distance above the water table, ranging from 0.20 to 1.5g m-3 d-1 for toluene, from 0.24 to 0.38 g m-3 d-1 for xylene, from 0.09 to 0.24 g m-3 d-1 for cyclohexene, from 0.05 to 0.22 g m-3 d-1 for ethylbenzene, and from 0.02 to 0.08 g m-3 d-1 for benzene. Rates were highest in the capillary zone, where 68% of the total hydrocarbon mass that volatilized from the water table was estimated to have been biodegraded. Hydrocarbons were nearly completely degraded within 1 m above the water table. This large loss underscores the importance of aerobic biodegradation in limiting the transport of hydrocarbon vapors in the unsaturated zone and implies that vapor-plume migration to basements and other points of contact may only be significant if a source of free product is present. Furthermore, because transport of the hydrocarbon in the unsaturated zone can be limited relative to that of oxygen and carbon dioxide, soil, gas surveys conducted at hydrocarbon-spill sites would benefit by the inclusion of oxygen- and carbon-dioxide-gas concentration measurements. Aerobic degradation kinetics in the unsaturated zone were approximately first-order. First-order rate constants near the water table were highest for cyctohexene (0.21-0.65 d-1) and nearly equivalent for ethylbenzene (0.11-20.31 d-1), xylenes (0.10-0.31 d-1), toluene (0.09-0.30 d-1), and benzene (0.07,0.31 d-1). Hydrocarbon mass loss rates at the water table resulting from the coupled aerobic biodegradation and volatilization process were determined by extrapolating gas transport rates through the capillary zone. Mass

  10. Effects of exogenous aerobic bacteria on methane production and biodegradation of municipal solid waste in bioreactors.

    PubMed

    Ge, Sai; Liu, Lei; Xue, Qiang; Yuan, Zhiming

    2016-09-01

    Landfill is the most common and efficient ways of municipal solid waste (MSW) disposal and the landfill biogas, mostly methane, is currently utilized to generate electricity and heat. The aim of this work is to study the effects and the role of exogenous aerobic bacteria mixture (EABM) on methane production and biodegradation of MSW in bioreactors. The results showed that the addition of EABM could effectively enhance hydrolysis and acidogenesis processes of MSW degradation, resulting in 63.95% reduction of volatile solid (VS), the highest methane production rate (89.83Lkg(-1) organic matter) ever recorded and a threefold increase in accumulative methane production (362.9L) than the control (127.1L). In addition, it is demonstrated that white-rot fungi (WRF) might further promote the methane production through highly decomposing lignin, but the lower pH value in leachate and longer acidogenesis duration may cause methane production reduced. The data demonstrated that methane production and biodegradation of MSW in bioreactors could be significantly enhanced by EABM via enhanced hydrolysis and acidogenesis processes, and the results are of great economic importance for the future design and management of landfill. PMID:26601890

  11. Numerical simulation of competitive aerobic / anaerobic hydrocarbon plume biodegradation in two-dimensional bench scale lab-experiments

    NASA Astrophysics Data System (ADS)

    Beyer, C.; Ballarini, E.; Bauer, R.; Griebler, C.; Bauer, S.

    2011-12-01

    The biodegradation of oxidizable hydrocarbon contaminants in the subsurface requires the presence of compatible microbial communities as well as sufficient amounts of electron acceptors and nutrients. In this context, transverse mixing, driven by dispersion and diffusion, is one of the main mechanisms governing the availability of dissolved electron acceptors at a hydrocarbon plume fringe. Aerobic and anaerobic biodegradation of hydrocarbons limited by transverse mixing has been studied experimentally in 2D bench-scale flow-through tanks, filled with a saturated porous medium. Flow of groundwater through the tanks was induced by pumping water at one side through injection ports, and simultaneously extracting water at the other side of the tank. An ethylbenzene plume was established by injection through the central inlet port. A mixture of unlabeled and fully deuterium-labeled isotopomers was used in order to investigate the spatial distribution of degradation processes via monitoring of compound-specific stable isotope fractionation. In the first phase of the experiment, aerobic biodegradation was studied. For this purpose, the tank was recharged with water containing oxygen as a dissolved electron acceptor and the aerobic strain Pseudomonas putida F1 was inoculated. Later, nitrate was added to the recharge water as an additional electron acceptor and the denitrifying strain Aromatoleum aromaticum EbN1 was amended to study competitive aerobic/anaerobic biodegradation. A numerical reactive transport model of the experiment was set up for a model based interpretation of the observed degradation patterns. In a sensitivity analysis, the influence of the relevant hydrodynamic parameters on the observable distributions of ethylbenzene isotopomers, oxygen and nitrate was studied. Subsequent model calibration allowed for a good agreement with ethylbenzene concentrations measured at the tank outlet ports as well as oxygen concentrations, which were measured at several

  12. Substrate interaction during aerobic biodegradation of creosote-related compounds in columns of sandy aquifer material

    NASA Astrophysics Data System (ADS)

    Millette, Denis; Butler, Barbara J.; Frind, E. O.; Comeau, Yves; Samon, Réjean

    1998-01-01

    A column study was initiated to study the effect of phenanthrene, fluorene, and p-cresol on the aerobic biodegradation of carbazole in columns of sandy aquifer material. Biodegradation of the contaminant mixture was sequential in space with p-cresol being preferentially degraded, followed by phenanthrene, then the other compounds. Both p-cresol and phenanthrene were completely biotransformed to non-detectable levels during passage through the 46 cm sand column but some carbazole and fluorene persisted throughout the approximately 3 month experiments. Influent p-cresol (10000ppb) was the only compound that affected adaptation of the microbial community to carbazole biodegradation, but its effect was of little practical importance, amounting to a 4.5 day difference in carbazole breakthrough. However, when influent p-cresol was at high levels (70 000 ppb), biotransformation of the other co-substrates in the mixture never ensued because p-cresol caused complete dissolved oxygen depletion. Conversely, influent p-cresol ultimately enhanced biotransformation of the other co-substrates in the mixture when present at a concentration (10000ppb) that did not deplete all available oxygen. The concentrations of the other, more recalcitrant compounds, ranging between 33 and 238 ppb, were probably too low to support bacterial growth so that slow, limited biotransformation resulted, although addition of an auxiliary substrate (i.e. the p-cresol) stimulated their biotransformation. Under quasi-steady-state conditions, the presence of phenanthrene in the influent inhibited fluorene biotransformation and possibly carbazole biotransformation. Results of the present study demonstrated also that interactions identified in static batch microcosms and in a hydrodynamic saturated column system can differ.

  13. Biodegradation of ethylene vinyl alcohol by aerobic organisms in an aqueous environment

    SciTech Connect

    Rhoades, J.J. Jr.; Young, J.C.

    1996-11-01

    Ethylene vinyl alcohol (EVOH) is a thermoplastic used extensively in laminates for food containers. This study investigates the biodegradability of EVOH utilizing ASTM Test Method D5271. This method indicates the extent and rate of biodegradation of plastic materials by aerobic microorganisms in an aqueous environment and is performed in a respirometer. The ethylene derived segments of the EVOH contain {sup 14}C which acts as tracer to measure biodegradation as indicated by the {sup 14}C-CO{sub 2} given off by microbial metabolism. Liquid scintillation counting measured the activity of the respired {sup 14}C-CO{sub 2} converted from the ethylene segments of the EVOH. Three physical forms of EVOH were tested: a pure EVOH, a high surface area EVOH, and a blended form of EVOH with polyvinyl alcohol (PVOH). The reactors with these EVOH forms were set up to receive a weekly influx of microorganisms (inoculum), or various amounts of POH as a co-substrate. Results to date have indicated that an increased surface area for the EVOH increases conversion of {sup 14}C relative to the pure EVOH. Some cases with blended EVOH/PVOH reactors have also showed increased conversion of {sup 14}C relative to the pure EVOH cases. The addition of inoculum to the reactors did not seem to significantly increase the conversion of {sup 14}C as compared to the effect of PVOH addition. PVOH co-substrate addition increased {sup 14}C conversion. Also, increasing the amount of PVOH co-substrate addition further increases the conversion of {sup 14}C.

  14. USE OF COMPOUND-SPECIFIC STABLE CARBON ISOTOPE ANALYSES TO DEMONSTRATE NATURAL BIODEGRADATION OF MTBE IN GROUND WATER AT A GASOLINE RELEASE SITE

    EPA Science Inventory

    Methyl tertiary butyl ether (MTBE) has been used as an additive in gasoline to enhance
    octane rating and to improve combustion efficiency. It is also a commonly detected contaminant in both surface water and ground water systems. This study presents concentration and stable ...

  15. Aerobic biodegradation potential of endocrine-disrupting chemicals in surface-water sediment at Rocky Mountain National Park, USA.

    PubMed

    Bradley, Paul M; Battaglin, William A; Iwanowicz, Luke R; Clark, Jimmy M; Journey, Celeste A

    2016-05-01

    Endocrine-disrupting chemicals (EDCs) in surface water and bed sediment threaten the structure and function of aquatic ecosystems. In natural, remote, and protected surface-water environments where contaminant releases are sporadic, contaminant biodegradation is a fundamental driver of exposure concentration, timing, duration, and, thus, EDC ecological risk. Anthropogenic contaminants, including known and suspected EDCs, were detected in surface water and sediment collected from 2 streams and 2 lakes in Rocky Mountain National Park (Colorado, USA). The potential for aerobic EDC biodegradation was assessed in collected sediments using 6 (14) C-radiolabeled model compounds. Aerobic microbial mineralization of natural (estrone and 17β-estradiol) and synthetic (17α-ethinylestradiol) estrogen was significant at all sites. Bed sediment microbial communities in Rocky Mountain National Park also effectively degraded the xenoestrogens bisphenol-A and 4-nonylphenol. The same sediment samples exhibited little potential for aerobic biodegradation of triclocarban, however, illustrating the need to assess a wider range of contaminant compounds. The present study's results support recent concerns over the widespread environmental occurrence of carbanalide antibacterials, like triclocarban and triclosan, and suggest that backcountry use of products containing these compounds should be discouraged. Environ Toxicol Chem 2016;35:1087-1096. Published 2015 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America. PMID:26588039

  16. Aerobic biodegradation potential of endocrine disrupting chemicals in surface-water sediment at Rocky Mountains National Park, USA

    USGS Publications Warehouse

    Bradley, Paul M.; Battaglin, William A.; Iwanowicz, Luke; Clark, Jimmy M.; Journey, Celeste A.

    2016-01-01

    Endocrine disrupting chemicals (EDC) in surface water and bed sediment threaten the structure and function of aquatic ecosystems. In natural, remote, and protected surface-water environments where contaminant releases are sporadic, contaminant biodegradation is a fundamental driver of exposure concentration, timing, duration, and, thus, EDC ecological risk. Anthropogenic contaminants, including known and suspected EDC, were detected in surface water and sediment collected from 2 streams and 2 lakes in Rocky Mountains National Park (ROMO). The potential for aerobic EDC biodegradation was assessed in collected sediments using 6 14C-radiolabeled model compounds. Aerobic microbial mineralization of natural (estrone and 17β-estradiol) and synthetic (17α-ethinylestradiol) estrogen was significant at all sites. ROMO bed sediment microbial communities also effectively degraded the xenoestrogens, bisphenol-A and 4-nonylphenol. The same sediment samples exhibited little potential for aerobic biodegradation of triclocarban, however, illustrating the need to assess a wider range of contaminant compounds. The current results support recent concerns over the widespread environmental occurrence of carbanalide antibacterials, like triclocarban and triclosan, and suggest that backcountry use of products containing these compounds should be discouraged.

  17. Aerobic biodegradability of methyldiethanolamine (MDEA) used in natural gas sweetening plants in batch tests and continuous flow experiments.

    PubMed

    Fürhacker, M; Pressl, A; Allabashi, R

    2003-09-01

    Mixtures of different amines including tertiary amines (methyldiethanolamine, MDEA) are commonly used for the removal of CO2 from gas mixtures or in gas sweetening processes for the extraction of CO2 and H2S. The absorber solutions used can be released into the industrial waste water due to continuous substitution of degraded MDEA, periodically cleaning processes or an accidental spill. In this study, the aerobic biodegradability of MDEA was investigated in a standardised batch test and a continuous flow experiment (40 l/d). The results of the batch test indicated that the MDEA-solution was non-biodegradable during the test period of 28 days, whereas the continuous flow experiments showed biodegradation of more than 96% based on TOC-measurements. This was probably due to the adaptation of the microorganisms to this particular waste water contamination during continuous flow experiment. PMID:12871741

  18. Biodegradation of dimethyl phthalate by Sphingomonas sp. isolated from phthalic-acid-degrading aerobic granules.

    PubMed

    Zeng, Ping; Moy, Benjamin Yan-Pui; Song, Yong-Hui; Tay, Joo-Hwa

    2008-10-01

    Phthalic acid esters (PAEs) contamination in water, air, and soil is one of the major environmental concerns in many countries. Besides the PAE biodegradation process, the PAE degrading bacteria have become one of the focuses of study. This study reports the successful isolation of one kind of indigenous bacterium PA-02 from phthalic acid (PA)-degrading aerobic granules. Based on its 16S ribosomal DNA sequence, isolate PA-02 was identified as Sphingomonas genus with 100% similarity to Sphingomonas sp. strain D84532. Strain PA-02 was a Gram-negative, rod-shaped bacterium with strong auto-aggregation ability. In particular, the strain PA-02 possessed PAE-degrading ability without acclimation. Results of growth tests showed that strain PA-02 could degrade dimethyl phthalate (DMP), dibutyl phthalate, and diethylhexyl phthalate. The specific degradation rates of DMP and PA were concentration-dependent with maximum values of 0.4 g-DMP g(-1) biomass h(-1) and 1.3 g-PA g(-1) biomass h(-1), respectively. Kinetic studies also revealed that PA-02 was robust under high concentrations of DMP and PA. Even when the PA concentration was increased to 1,000.0 mg l(-1), the specific PA degradation rate was about 0.25 g-PA g(-1) biomass h(-1). The corresponding value for DMP was 0.067 g-DMP g(-1) biomass h(-1) at 1,000 mg l(-1). PMID:18751698

  19. Inhibition of aerobic metabolic cis-1,2-di-chloroethene biodegradation by other chloroethenes.

    PubMed

    Zhao, He-Ping; Schmidt, Kathrin R; Tiehm, Andreas

    2010-04-01

    The presence of other chloroethenes influences aerobic metabolic biodegradation of cis-1,2-dichloroethene (cDCE). A new metabolically cDCE degrading enrichment culture was identified as also being capable of degrading vinyl chloride (VC), but not 1,1-dichloroethene (1,1DCE), trans-1,2-dichloroethene (tDCE), trichloroethene (TCE), or tetrachloroethene (PCE). The fastest degradation of cDCE was observed in the absence of any other chloroethene. In the presence of a second chloroethene (40-90 microM), the rate of cDCE (60 microM) degradation decreased in the following order: cDCE (+PCE) > cDCE (+tDCE) > cDCE (+VC)>cDCE (+1,1DCE) approximately cDCE (+TCE). With increasing concentrations of VC, ranging from 10 to 110 microM, the rate of cDCE (60 microM) degradation decreased. This study demonstrates that the inhibiting effects of chloroethene mixtures have to be considered during laboratory studies and bioremediation approaches based on metabolic cDCE degradation. PMID:20079512

  20. KEY CONCEPTS IN BIODEGRADATION

    EPA Science Inventory

    This one hour segment of the course identifies the biological processes that degrade petroleum hydrocarbons and MTBE. It reviews the stoichiometry of hydrocarbon degradation by aerobic respiration, nitrate reduction, sulfate reduction, iron (III) reduction, and methanogenesis. ...

  1. Dissolved organic matter removal during coal slag additive soil aquifer treatment for secondary effluent recharging: Contribution of aerobic biodegradation.

    PubMed

    Wei, Liangliang; Li, Siliang; Noguera, Daniel R; Qin, Kena; Jiang, Junqiu; Zhao, Qingliang; Kong, Xiangjuan; Cui, Fuyi

    2015-06-01

    Recycling wastewater treatment plant (WWTP) effluent at low cost via the soil aquifer treatment (SAT), which has been considered as a renewable approach in regenerating potable and non-potable water, is welcome in arid and semi-arid regions throughout the world. In this study, the effect of a coal slag additive on the bulk removal of the dissolved organic matter (DOM) in WWTP effluent during SAT operation was explored via the matrix configurations of both coal slag layer and natural soil layer. Azide inhibition and XAD-resins fractionation experiments indicated that the appropriate configuration designing of an upper soil layer (25 cm) and a mixture of soil/coal slag underneath would enhance the removal efficiency of adsorption and anaerobic biodegradation to the same level as that of aerobic biodegradation (31.7% vs 32.2%), while it was only 29.4% compared with the aerobic biodegradation during traditional 50 cm soil column operation. The added coal slag would preferentially adsorb the hydrophobic DOM, and those adsorbed organics could be partially biodegraded by the biomass within the SAT systems. Compared with the relatively lower dissolved organic carbon (DOC), ultraviolet light adsorption at 254 nm (UV-254) and trihalomethane formation potential (THMFP) removal rate of the original soil column (42.0%, 32.9%, and 28.0%, respectively), SSL2 and SSL4 columns would enhance the bulk removal efficiency to more than 60%. Moreover, a coal slag additive in the SAT columns could decline the aromatic components (fulvic-like organics and tryptophan-like proteins) significantly. PMID:25845997

  2. Two-Dimensional Stable Isotope Fractionation During Aerobic and Anaerobic Alkane Biodegradation and Implications for the Field

    NASA Astrophysics Data System (ADS)

    El Morris, Brandon; Suflita, Joseph M.; Richnow, Hans-Hermann

    2010-05-01

    Quantitatively, n-alkanes comprise a major portion of most crude oils. In petroliferous formations, it may be possible to relate the loss of these compounds to the levels of biodegradation occurring in situ [1]. Moreover, it is important to develop indicators of alkane degradation that may be used to monitor bioremediation of hydrocarbon-impacted environments. Desulfoglaeba alkanexedens and Pseudomonas putida GPo1 were used to determine if carbon and hydrogen stable isotope fractionation could differentiate between n-alkane degradation under anaerobic and aerobic conditions, respectively in the context of the Rayleigh equation model [2]. Bacterial cultures were sacrificed by acidification and headspace samples were analyzed for stable isotope composition using gas chromatography-isotope ratio mass spectrometry. Carbon enrichment factors (bulk) for anaerobic and aerobic biodegradation of hexane were -5.52 ± 0.2‰ and -4.34 ± 0.3‰, respectively. Hydrogen enrichment during hexane degradation was -43.14 ± 6.32‰ under sulfate-reducing conditions, and was too low for quantification during aerobiosis. Collectively, this indicates that the correlation between carbon and hydrogen stable isotope fractionation (may be used to help elucidate in situ microbial processes in oil reservoirs, and during intrinsic as well as engineered remediation efforts. References 1. Asif, M.; Grice, K.; Fazeelat, T., Assessment of petroleum biodegradation using stable hydrogen isotopes of individual saturated hydrocarbon and polycyclic aromatic hydrocarbon distributions in oils from the Upper Indus Basin, Pakistan. Organic Geochemistry 2009, 40, (3), 301-311. 2. Fischer, A.; Herklotz, I.; Herrmann, S.; Thullner, M.; Weelink, S. A. B.; Stams, A., J. M.; Schloemann, M.; Richnow, H.-H.; Vogt, C., Combined carbon and hydrogen isotope fractionation investigations for elucidating benzene biodegradation pathways. Environ. Sci. Technol. 2008, 42, 4356-4363.

  3. Aerobic biodegradation kinetics of solid organic wastes on earth and for applications in space

    NASA Astrophysics Data System (ADS)

    Ramirez Perez, Javier Christian

    Aerobic biodegradation plays an important role in recycling organic matter and nutrients on earth. It is also a candidate technology for waste processing and resource recovery in Advanced Life Support (ALS) systems, such as a proposed planetary base on Mars. Important questions are how long should wastes be treated, and what is the quality (stability/maturity) of the product. To address these questions two aerobic composting systems were evaluated. One treated (252 days) horse manure and cranberry fruit in duplicate open windrows (HCC) as a reference earth application. The other was a pilot-scale (330 L) enclosed, in-vessel system treating (162 days) inedible biomass collected from plant growth systems at NASA, amended with food and human wastes simulant for potential space application (ALSC). Samples were taken from both systems over time and product quality assessed with a range of physical, chemical, biological, toxicological, respirometry and plant growth analyses that were developed and standardized. Because plant growth analyses take so long, a hypothesis was that some parameters could be used to predict compost quality and suitability for growing plants. Maximum temperatures in the thermophilic range were maintained for both systems (HCC > 60°C for >129 days, ALSC > 55°C for >40 days. Fecal streptococci were reduced by 4.8 log-units for HCC and 7.8 for ALSC. Volume/mass reductions achieved were 63%/62% for HCC and 79%/67% for ALSC. Phytotoxicity tests performed on aqueous extracts to recover plant nutrients found decreasing sensitivity: arabidopsis > lettuce > tomato > wheat > cucumber, corresponding with seed size and food reserve capacity. The germination index (GI) of HCC increased over composting time indicating decreasing phytotoxicity. However, GIs for ALSC leachate decreased or fluctuated over composting time. Selected samples of HCC at 31, 157 and 252 days alone and combined with promix (1:1), and of ALSC at 7, 14, 21, 28, 40 and 84 days, or fresh

  4. NATURAL ATTENUATION OF MTBE

    EPA Science Inventory

    For the case studies, the MTBE, TBA, and BTEX plume will be studied in a longitudinal transect along the center-line of the plume, and at least two transects perpendicular to ground water flow. Water samples will be analyzed for the concentration of MTBE, TBA, BTEX, methane, sulf...

  5. THE PARADOXES OF MTBE

    EPA Science Inventory

    A widely used gasoline additive, methyl tertiary butyl ether (MTBE), has been controversial, in part because of concerns about potential inhalation health effects and more recently because of added concerns about water contamination. Although many of the issues related to MTBE ha...

  6. COST OF MTBE REMEDIATION

    EPA Science Inventory

    Widespread contamination of methyl tert-butyl ether (MTBE) in ground water has raised concerns about the increased cost of remediation of MTBE releases compared to BTEX-only sites. To evaluate these cost, cost information for 311 sites was furnished by U.S. EPA Office of Undergr...

  7. Aquatic photochemistry, abiotic and aerobic biodegradability of thalidomide: identification of stable transformation products by LC-UV-MS(n).

    PubMed

    Mahmoud, Waleed M M; Trautwein, Christoph; Leder, Christoph; Kümmerer, Klaus

    2013-10-01

    Thalidomide (TD), besides being notorious for its teratogenicity, was shown to have immunomodulating and anti-inflammatory activities. This is why recently TD became a promising drug for the treatment of different cancers and inflammatory diseases. Yet nothing is known about the environmental fate of TD, which therefore was assessed experimentally and by in silico prediction programs (quantitative structure activity relationship (QSAR) models) within this study. Photolytic degradation was tested with two different light sources (medium-pressure mercury lamp; xenon lamp) and aerobic biodegradability was investigated with two OECD tests (Closed Bottle test (CBT), Manometric Respirometry test (MRT)). An additional CBT was performed for TD samples after 16 min of UV-photolysis. The primary elimination of TD was monitored and the structures of its photo-, abiotic and biodegradation products were elucidated by HPLC-UV-Fluorescence-MS(n). Furthermore, elimination of dissolved organic carbon was monitored in the photolysis experiment. LC-MS revealed that new photolytic transformation products (TPs) were identified, among them two isomers of TD with the same molecular mass. These TPs were different to the products formed by biodegradation. The experimental findings were compared with the results obtained from the in silico prediction programs where e.g. a good correlation for TD biodegradation in the CBT was confirmed. Moreover, some of the identified TPs were also structurally predicted by the MetaPC software. These results demonstrate that TD and its TPs are not readily biodegradable and not fully mineralized by photochemical treatment. They may therefore pose a risk to the aquatic environment due to the pharmacological activity of TD and unknown properties of its TPs. The applied techniques within this study emphasize the importance of QSAR models as a tool for estimating environmental risk assessments. PMID:23792256

  8. Microrespirometric determination of the effectiveness factor and biodegradation kinetics of aerobic granules degrading 4-chlorophenol as the sole carbon source.

    PubMed

    Vital-Jacome, Miguel; Buitrón, Germán; Moreno-Andrade, Ivan; Garcia-Rea, Victor; Thalasso, Frederic

    2016-08-01

    In this study, a microrespirometric method was used, i.e., pulse respirometry in microreactors, to characterize mass transfer and biodegradation kinetics in aerobic granules. The experimental model was an aerobic granular sludge in a sequencing batch reactor (SBR) degrading synthetic wastewater containing 4-chlorophenol as the sole carbon source. After 15 days of acclimation, the SBR process degraded 4-chlorophenol at a removal rate of up to 0.9kg CODm(-3)d(-1), and the degradation kinetics were well described by the Haldane model. The microrespirometric method consisted of injecting pulses of 4-chlorophenol into the 24 wells of a microreactor system containing the SBR samples. From the respirograms obtained, the following five kinetic parameters were successfully determined during reactor operation: (i) Maximum specific oxygen uptake rate, (ii) substrate affinity constant, (iii) substrate inhibition constant, (iv) maximum specific growth rate, and (v) cell growth yield. Microrespirometry tests using granules and disaggregated granules allowed for the determination of apparent and intrinsic parameters, which in turn enabled the determination of the effectiveness factor of the granular sludge. It was concluded that this new high-throughput method has the potential to elucidate the complex biological and physicochemical processes of aerobic granular biosystems. PMID:27054670

  9. Kinetics of aerobic cometabolic biodegradation of chlorinated and brominated aliphatic hydrocarbons: A review.

    PubMed

    Jesus, João; Frascari, Dario; Pozdniakova, Tatiana; Danko, Anthony S

    2016-05-15

    This review analyses kinetic studies of aerobic cometabolism (AC) of halogenated aliphatic hydrocarbons (HAHs) from 2001-2015 in order to (i) compare the different kinetic models proposed, (ii) analyse the estimated model parameters with a focus on novel HAHs and the identification of general trends, and (iii) identify further research needs. The results of this analysis show that aerobic cometabolism can degrade a wide range of HAHs, including HAHs that were not previously tested such as chlorinated propanes, highly chlorinated ethanes and brominated methanes and ethanes. The degree of chlorine mineralization was very high for the chlorinated HAHs. Bromine mineralization was not determined for studies with brominated aliphatics. The examined research period led to the identification of novel growth substrates of potentially high interest. Decreasing performance of aerobic cometabolism were found with increasing chlorination, indicating the high potential of aerobic cometabolism in the presence of medium- and low-halogenated HAHs. Further research is needed for the AC of brominated aliphatic hydrocarbons, the potential for biofilm aerobic cometabolism processes, HAH-HAH mutual inhibition and the identification of the enzymes responsible for each aerobic cometabolism process. Lastly, some indications for a possible standardization of future kinetic studies of HAH aerobic cometabolism are provided. PMID:26874310

  10. AEROBIC BIODEGRADATION OF NATURAL AND XENOBIOTIC ORGANIC COMPOUNDS BY SUBSURFACE MICROBIAL COMMUNITIES

    EPA Science Inventory

    Studies were conducted to characterize the diversity of degradative abilities of microbial communities from pristine aquifer solids samples. Biodegradation was measured in aquifer solids slurries as both the conversion of radiolabeled substrate to (14)CO2 and the incorporation of...

  11. Potential contribution of microbial degradation to natural attenuation of MTBE in surface water systems

    USGS Publications Warehouse

    Bradley, P.M.; Chapelle, F.H.; Landmeyer, J.E.

    2001-01-01

    The potential contribution of in situ biodegradation as a mechanism for natural attenuation of MTBE in surface water was studied. Surface water sediments from streams and lakes at 11 sites throughout the US. Microbial degradation of [U-14C] MTBE was observed in surface-water-sediment microcosms under anaerobic conditions, but the efficiency and products of anaerobic MTBE biodegradation were strongly dependent on the predominant terminal electron accepting conditions. In the presence of substantial methanogenic activity, MTBE biodegradation was nominal and involved reduction of MTBE to t-butanol (TBA). Under more oxidizing conditions, minimal accumulation of 14C-TBA and significant mineralization of [U-14C] MTBE to 14CO2 were observed. Microorganisms inhabiting the bed sediments of streams and lakes could degrade MTBE effectively under a range of anaerobic terminal electron accepting conditions. Thus, anaerobic bed sediment microbial processes also might contribute to natural attenuation of MTBE in surface water systems throughout the US. This is an abstract of a paper presented at the 222nd ACS National Meting (Chicago, IL 8/26-30/2001).

  12. Hydrocarbon Specificity During Aerobic oil Biodegradation Revealed in Marine Microcosms With the use of Comprehensive, Two-Dimensional Gas Chromatography.

    NASA Astrophysics Data System (ADS)

    Wardlaw, G. D.; Reddy, C. M.; Nelson, R. K.; Valentine, D. L.

    2008-12-01

    In 2003 the National Research Council reported more than 380 million gallons of oil is emitted into the ocean each year from natural seepage and as a result of anthropogenic activities. Many of the hydrocarbons making up this oil are persistent and toxic to marine life. Petroleum emitted into biologically sensitive areas can lead to environmental stress and ecosystem collapse. As a result many studies and a substantial amount of resources have been devoted to creating efficient and effective remediation tools and developing a better understanding of natural hydrocarbon weathering processes occurring in marine environments. The goal of this study is to elucidate patterns and extent of aerobic hydrocarbon degradation in marine sediments. In order to assess the specific molecular transformations occurring in petroleum emitted into oxic marine environments, we prepared microcosm experiments using sediments and seawater collected from the natural oil seeps offshore Coal Oil Point, California. Petroleum recovered from Platform Holly in the Santa Barbara Channel, was added to a sediment-seawater mixture and the microcosm bottles were allowed to incubate under aerobic conditions for slightly more than 100 days. Comprehensive, two-dimensional gas chromatography was employed in this study to quantify changes in the concentrations of individual hydrocarbon compounds because of the increased resolution and resolving power provided with this robust analytical method. We show significant hydrocarbon mass loss due to aerobic biodegradation for hundreds of tracked compounds in the microcosm bottles. The results shown here provide quantitative evidence for broad-scale metabolic specificity during aerobic hydrocarbon degradation in surface and shallow subsurface marine sediments.

  13. Widespread potential for microbial MTBE degradation in surface-water sediments

    USGS Publications Warehouse

    Bradley, P.M.; Landmeyer, J.E.; Chapelle, F.H.

    2001-01-01

    Microorganisms indigenous to stream and lake bed sediments, collected from 11 sites throughout the United States, demonstrated significant mineralization of the fuel oxygenate, methyl-tert-butyl ether (MTBE). Mineralization of [U-14C]MTBE to 14CO2 ranged from 15 to 66% over 50 days and did not differ significantly between sediments collected from MTBE contaminated sites and from sites with no history of MTBE exposure. This result suggests that even the microbial communities indigenous to newly contaminated surface water systems will exhibit some innate ability to attenuate MTBE under aerobic conditions. The magnitude of MTBE mineralization was related to the sediment grain size distribution. A pronounced, inverse correlation (p < 0.001; r2 = 0.73) was observed between the final recovery of 14CO2 and the percentage content of silt and clay sized grains (grain diameter < 0.125 mm). The results of this study indicate that the microorganisms that inhabit the bed sediments of streams and lakes can degrade MTBE efficiently and that this capability is widespread in the environment. Thus aerobic bed sediment microbial processes may provide a significant environmental sink for MTBE in surface water systems throughout the United States and may contribute to the reported transience of MTBE in some surface waters.

  14. TBA biodegradation in surface-water sediments under aerobic and anaerobic conditions

    USGS Publications Warehouse

    Bradley, P.M.; Landmeyer, J.E.; Chapelle, F.H.

    2002-01-01

    The potential for [U-14C] TBA biodegradation was examined in laboratory microcosms under a range of terminal electron accepting conditions. TBA mineralization to CO2 was substantial in surface-water sediments under oxic, denitrifying, or Mn(IV)-reducing conditions and statistically significant but low under SO4-reducing conditions. Thus, anaerobic TBA biodegradation may be a significant natural attenuation mechanism for TBA in the environment, and stimulation of in situ TBA bioremediation by addition of suitable terminal electron acceptors may be feasible. No degradation of [U-14C] TBA was observed under methanogenic or Fe(III)-reducing conditions.

  15. NATURAL ATTENUATION OF MTBE IN THE SUBSURFACE UNDER METHANOGENIC CONDITIONS

    EPA Science Inventory

    This case study was conducted at the former Fuel Farm Site at the U.S.Coast Guard Support Center at Elizabeth City, North Carolina. The study is intended to answer the following questions. Can MTBE be biodegraded under methanogenic conditions in ground water that was contaminated...

  16. Monitoring of the aerobe biodegradation of chlorinated organic solvents by stable isotope analysis

    NASA Astrophysics Data System (ADS)

    Horváth, Anikó; Futó, István; Palcsu, László

    2014-05-01

    Our chemical-biological basic research aims to eliminate chlorinated environmental contaminants from aquifers around industrial areas in the frame of research program supported by the European Social Fund (TÁMOP-4.2.2.A-11/1/KONV-2012-0043). The most careful and simplest way includes the in situ biodegradation with the help of cultured and compound specific strains. Numerous members of Pseudomonas bacteria are famous about function of bioremediation. They can metabolism the environmental hazardous chemicals like gas oils, dyes, and organic solvents. Our research based on the Pseudomonas putida F1 strain, because its ability to degrade halogenated hydrocarbons such as trichloroethylene. Several methods were investigated to estimate the rate of biodegradation, such as the measurement of the concentration of the pollutant along the contamination pathway, the microcosm's studies or the compound specific stable isotope analysis. In this area in the Transcarpathian basin we are pioneers in the stable isotope monitoring of biodegradation. The main goal is to find stable isotope fractionation factors by stable isotope analysis, which can help us to estimate the rate and effectiveness of the biodegradation. The subsequent research period includes the investigation of the method, testing its feasibility and adaptation in the environment. Last but not least, the research gives an opportunity to identify the producer of the contaminant based on the stable isotope composition of the contaminant.

  17. Biodegradation of phenols in a sandstone aquifer under aerobic conditions and mixed nitrate and iron reducing conditions

    NASA Astrophysics Data System (ADS)

    Broholm, Mette M.; Arvin, Erik

    2000-08-01

    Ammonia liquor with very high concentrations of phenol and alkylated phenols is known to have leaked into the subsurface at a former coal carbonization plant in the UK, giving high concentrations of ammonium in the groundwater. In spite of this, no significant concentrations of phenols were found in the groundwater. The potential for biodegradation of the phenols in the sandstone aquifer at the site has been investigated in laboratory microcosms under aerobic (oxygen amended) and mixed nitrate and iron reducing (nitrate enriched and unamended) anaerobic conditions, at a range of concentrations (low: ˜5 mg l -1, high: ˜60 mg l -1, and very high: ˜600 mg l -1) and in the presence of other organic coal-tar compounds (mono- and polyaromatic hydrocarbons (BTEXs and PAHs) and heterocyclic compounds (NSOs)) and ammonia liquor. Sandstone cores and groundwater for the microcosms were collected from within the anaerobic ammonium plume at the field site. Fast and complete degradation of phenol, o- and p-cresol, 2,5- and 3,4-xylenol with no or very short initial lag-phases was observed under aerobic conditions at low concentrations. 2,6- and 3,5-Xylenol were degraded more slowly and 3,5-xylenol degradation was only just complete after about 1 year. The maximum rates of total phenols degradation in duplicate aerobic microcosms were 1.06 and 1.76 mg l -1 day -1. The degradation of phenols in nitrate enriched and unamended anaerobic microcosms was similar. Fast and complete biodegradation of phenol, cresols, 3,4-xylenol and 3,5-xylenol was observed after short lag-phases in the anaerobic microcosms. 2,5-xylenol was partially degraded after a longer lag-phase and 2,6-xylenol persisted throughout the 3 month long experiments. The maximum rates of total phenols degradation in duplicate nitrate enriched and unamended anaerobic microcosms were 0.30-0.38 and 0.29-0.31 mg l -1 day -1, respectively. The highest phenols concentrations in the anaerobic microcosms apparently required

  18. Aerobic biodegradation of chlorinated ethenes in a fractured bedrock aquifer: quantitative assessment by compound-specific isotope analysis (CSIA) and reactive transport modeling.

    PubMed

    Pooley, Kathryn E; Blessing, Michaela; Schmidt, Torsten C; Haderlein, Stefan B; Macquarrie, Kerry T B; Prommer, Henning

    2009-10-01

    A model-based analysis of concentration and isotope data was carried out to assess natural attenuation of chlorinated ethenes in an aerobic fractured bedrock aquifer. Tetrachloroethene (PCE) concentrations decreased downgradient of the source, but constant delta13C signatures indicated the absence of PCE degradation. In contrast, geochemical and isotopic data demonstrated degradation of trichloroethene (TCE) and cis-1,2-dichloroethene (DCE) under the prevailing oxic conditions. Numerical modeling was employed to simulate isotopic enrichment of chlorinated ethenes and to evaluate alternative degradation pathway scenarios. Existing field information on groundwater flow, solute transport, geochemistry, and delta13C signatures of the chlorinated ethenes was integrated via reactive transport simulations. The results provided strong evidence for the occurrence of aerobic TCE and DCE degradation. The chlorinated ethene concentrations together with stable carbon isotope data allowed us to reliably constrain the assessment of the extent of biodegradation at the site and plume simulations quantitatively linked aerobic biodegradation with isotope signatures in the field. Our investigation provides the first quantitative assessment of aerobic biodegradation of chlorinated ethenes in a fractured rock aquifer based on compound specific stable isotope measurements and reactive transport modeling. PMID:19848161

  19. The Chemistry and Flow Dynamics of Molecular Biological Tools Used to Confirm In Situ Bioremediation of Benzene, TBA, and MTBE

    NASA Astrophysics Data System (ADS)

    North, K. P.; Mackay, D. M.; Scow, K. M.

    2010-12-01

    In situ bioremediation has typically been confirmed by collecting sediment and groundwater samples to directly demonstrate a degradation process in a laboratory microcosm. However, recent advances in molecular biological tools present options for demonstrating degradation processes with field-based tools that are less time-consuming. We have been investigating the capability of some of these molecular biological tools to evaluate in situ biodegradation of tert-butyl alcohol (TBA), methyl tert-butyl ether (MTBE), and benzene at two field sites in California. At both sites, we have deployed Bio-Traps® (“traps”), made of Bio-Sep® beads in slotted PVC pipe, which provide ideal environments for microbial colonization. Stable Isotope Probing can be accomplished by sorbing the13C-labeled organic contaminant of concern onto Bio-Sep® beads (“baiting”); incorporation of 13C into the biomass collected by the trap would indicate that the microbial community was capable of degrading the labeled compound. In addition, we examined the chemistry and flow dynamics of these traps and present those results here. We performed a field experiment and a lab experiment to, in part, define the rate that different baits leached off various traps. At a TBA- and MTBE-contaminated site at Vandenberg AFB, Lompoc, CA, the TBA-dominant plume was effectively treated by recirculation/oxygenation of groundwater, decreasing TBA and MTBE concentrations to detection limits along predicted flowpaths created by two pairs of recirculation wells. We used the generated aerobic treatment zone to deploy traps baited with 13C-labeled MTBE or TBA in a novel, ex situ experimental setup. The groundwater flow extracted from the aerobic treatment zone was split through several chambers, each containing a trap and monitoring of influent and effluent. The chamber effluent was measured throughout a six-week deployment and analyzed for both TBA and MTBE; the majority of mass leached from the baited traps did

  20. Biodegradation of pulp and paper mill effluent using anaerobic followed by aerobic digestion.

    PubMed

    Bishnoi, Narsi R; Khumukcham, R K; Kumar, Rajender

    2006-05-01

    An experimental study was carried to find out the degradability of black liquor of pulp and paper mill wastewater for biomethanogenesis in continuous stirred tank reactor (CSTR) and followed by activated sludge process (ASP). Continuous stirred tank reactor was used in present study for anaerobic digestion of black liquor, while completely mixed activated sludge system was used for aerobic digestion. A maximum methane production was found up to 430 ml/day, chemical oxygen demand was reduced up to 64% and total volatile fatty acid increased up to 1500 mg/l from 975 mg/l at 7.3 pH, 37 degrees C temperature and 8 days hydraulic retention time during anaerobic digestion. In activated sludge process (aerobic digestion) chemical oxygen demand and biological oxygen demand reduction were 81% and 86% respectively at 72 hr hydraulic retention time. PMID:17436533

  1. Integrated anaerobic-aerobic process for the biodegradation of chlorinated aromatic compounds

    SciTech Connect

    Armenante, P.M.; Lewandowski, G.; Chengming Kung ); Kafkewitz, D. )

    1992-05-01

    An integrated anaerobic-aerobic process for the complete mineralization of 2,4,6-trichlorophenol was successfully tested and operated. The sludge obtained from the anaerobic digester of a commercial treatment plant was used to obtain an anaerobic consortium capable of partially dechlorinating 2,4,6-trichlorophenol (2,4,6-TCP). The clarified and sterilized effluent from the same anaerobic digester was used as the medium for the anaerobic consortium. During the anaerobic process 2,4,6-TCP was first dechlorinated to 2,4-dichlorophenol and then to 4-chlorophenol (4CP). Stoichiometric amounts of 4-CP were recovered. Similar results were obtained when the anaerobic microorganisms were immobilized on Manville R-635 silica beads. After immobilization, the consortium was able to dechlorinate 150{mu}M of 2,4,6-TCP in four days. Pseudomonas Glathei and an indigenous culture obtained from same sludge used to produce the anaerobic enrichment culture were shown to be able to degrade the 4-CP produced from the anaerobic dechlorination of 2,4,6-TCP. However, for the aerobic 4-CP mineralization to occur the medium had to be buffered with phosphate, since high pH would inhibit the aerobic bacterial activity. It is expected that the proposed approach will be used to treat recalcitrant halogenated compounds that are not amenable to conventional biological treatment.

  2. Aerobic biodegradation of 2,2'-dithiodibenzoic acid produced from dibenzothiophene metabolites

    SciTech Connect

    Young, R.F.; Cheng, S.M.; Fedorak, P.M.

    2006-01-15

    Dibenzothiophene is a sulfur heterocycle found in crude oils and coal. The biodegradation of dibenzothiophene through the Kodama pathway by Pseudomonas sp. strain BT1d leads to the formation of three disulfides: 2-oxo-2-(2-thiophenyl)ethanoic acid disulfide, 2-oxo-2-(2-thiophenyl)ethanoic acid-2-benzoic acid disulfide, and 2,2'-dithiodibenzoic acid. When provided as the carbon and sulfur source in liquid medium, 2,2'-dithiodibenzoic acid was degraded by soil enrichment cultures. Two bacterial isolates, designated strains RM1 and RM6, degraded 2,2'-dithiodibenzoic acid when combined in the medium. Isolate RM6 was found to have an absolute requirement for vitamin B{sub 12}, and it degraded 2,2'-dithiodibenzoic acid in pure culture when the medium was supplemented with this vitamin. Isolate RM6 also degraded 2,2'-dithiodibenzoic acid in medium containing sterilized supernatants from cultures of isolate RM1 grown on glucose or benzoate. Isolate RM6 was identified as a member of the genus Variovorax using the Biolog system and 16S rRNA gene analysis. Although the mechanism of disulfide metabolism could not be determined, benzoic acid was detected as a transient metabolite of 2,2'-dithiodibenzoic acid biodegradation by Variovorax sp. strain RM6. In pure culture, this isolate mineralized 2,2'-dithiodibenzoic acid, releasing 59% of the carbon as carbon dioxide and 88% of the sulfur as sulfate.

  3. NATURAL ATTENUATION OF MTBE

    EPA Science Inventory

    Three cases of MTBE contamination of ground water are presented. Each case site had own characteristics and different geochemical condition. The first case site was where dissolved oxygen was the dominant electron acceptor, while the sites of the second and third cases were und...

  4. Aerobic Biodegradation of 2,4-Dinitroanisole by Nocardioides sp. Strain JS1661

    PubMed Central

    Fida, Tekle Tafese; Palamuru, Shannu; Pandey, Gunjan

    2014-01-01

    2,4-Dinitroanisole (DNAN) is an insensitive munition ingredient used in explosive formulations as a replacement for 2,4,6-trinitrotoluene (TNT). Little is known about the environmental behavior of DNAN. There are reports of microbial transformation to dead-end products, but no bacteria with complete biodegradation capability have been reported. Nocardioides sp. strain JS1661 was isolated from activated sludge based on its ability to grow on DNAN as the sole source of carbon and energy. Enzyme assays indicated that the first reaction involves hydrolytic release of methanol to form 2,4-dinitrophenol (2,4-DNP). Growth yield and enzyme assays indicated that 2,4-DNP underwent subsequent degradation by a previously established pathway involving formation of a hydride-Meisenheimer complex and release of nitrite. Identification of the genes encoding the key enzymes suggested recent evolution of the pathway by recruitment of a novel hydrolase to extend the well-characterized 2,4-DNP pathway. PMID:25281383

  5. Biodegradation of bisphenol A and other bisphenols by a gram-negative aerobic bacterium

    SciTech Connect

    Lobos, J.H.; Leib, T.K. ); Tahmun Su )

    1992-06-01

    A novel bacterium designated strain MV1 was isolated from a sludge enrichmet takes from the wastewater treatment plant at a plastics manufacturing facility and shown to degrade 2,2-bis(4-hydroxyphenyl)propane (4,4[prime]-isopropylidenediphenol or bisphenol A). Strain MV1 is a gram-negative, aerobic bacillus that grows on bisphenol A as a sole source of carbon and energy. Total carbon analysis for bisphenol A degradation demonstrated that 60% of the carbon was mineralized to CO[sub 2], 20% was associated with the bacterial cells, and 20% was converted to soluble organic compounds. Metabolic intermediates detected in the culture medium during growth on bisphenol A were identified as 4-hydroxybenzoic acid, 4-hydroxyacetophenone, 2,2-bis(4-hydroxyphenyl)-1-propanol, and 2,3-bis(4-hydroxyphenyl)-1,2-propanediol. Most of the bisphenol A degraded by strain MV1 is cleaved in some way to form 4-hydroxybenzoic acid and 4-hydroxyacetophenone, which are subsequently mineralized or assimilated into cell carbon. In addition, about 20% of the bisphenol A is hydroxylated to form 2,2-bis(4-hydroxyphenyl)-1-propanol, which is slowly biotransformed to 2,3-bis(4-hydroxyphenyl)-1,2-propanediol. Cells that were grown on bisphenol A degraded a variety of bisphenol alkanes, hydroxylated benzoic acids, and hydroxylated acetophenones during resting-cell assays. Transmission electron microscopy of cells grown on bisphenol A revealed lipid storage granules and intracytoplasmic membranes.

  6. Biodegradation of bisphenol A and other bisphenols by a gram-negative aerobic bacterium.

    PubMed

    Lobos, J H; Leib, T K; Su, T M

    1992-06-01

    A novel bacterium designated strain MV1 was isolated from a sludge enrichment taken from the wastewater treatment plant at a plastics manufacturing facility and shown to degrade 2,2-bis(4-hydroxyphenyl)propane (4,4'-isopropylidenediphenol or bisphenol A). Strain MV1 is a gram-negative, aerobic bacillus that grows on bisphenol A as a sole source of carbon and energy. Total carbon analysis for bisphenol A degradation demonstrated that 60% of the carbon was mineralized to CO2, 20% was associated with the bacterial cells, and 20% was converted to soluble organic compounds. Metabolic intermediates detected in the culture medium during growth on bisphenol A were identified as 4-hydroxybenzoic acid, 4-hydroxyacetophenone, 2,2-bis(4-hydroxyphenyl)-1-propanol, and 2,3-bis(4-hydroxyphenyl)-1,2-propanediol. Most of the bisphenol A degraded by strain MV1 is cleaved in some way to form 4-hydroxybenzoic acid and 4-hydroxyacetophenone, which are subsequently mineralized or assimilated into cell carbon. In addition, about 20% of the bisphenol A is hydroxylated to form 2,2-bis(4-hydroxyphenyl)-1-propanol, which is slowly biotransformed to 2,3-bis(4-hydroxyphenyl)-1,2-propanediol. Cells that were grown on bisphenol A degraded a variety of bisphenol alkanes, hydroxylated benzoic acids, and hydroxylated acetophenones during resting-cell assays. Transmission electron microscopy of cells grown on bisphenol A revealed lipid storage granules and intracytoplasmic membranes. PMID:1622258

  7. Biodegradable polymers from organic acids by using activated sludge enriched by aerobic periodic feeding.

    PubMed

    Dionisi, Davide; Majone, Mauro; Papa, Viviana; Beccari, Mario

    2004-03-20

    This article describes a new process for the production of biopolymers (polyhydroxyalkanoates, PHAs) based on the aerobic enrichment of activated sludge to obtain mixed cultures able to store PHAs at high rates and yields. Enrichment was obtained through the selective pressure established by feeding the carbon source in a periodic mode (feast and famine regime) in a sequencing batch reactor. A concentrated mixture of acetic, lactic, and propionic acids (overall concentration of 8.5 gCOD L(-1)) was fed every 2 h at 1 day(-1) overall dilution rate. Even at such high organic load (8.5 gCOD L(-1) day(-1)), the selective pressure due to periodic feeding was effective in obtaining a biomass with a storage ability much higher than activated sludges. The immediate biomass response to substrate excess (as determined thorough short-term batch tests) was characterized by a storage rate and yield of 649 mgPHA (as COD) g biomass (as COD)(-1) h(-1) and 0.45 mgPHA (as COD) mg removed substrates (as COD(-1)), respectively. When the substrate excess was present for more than 2 h (long-term batch tests), the storage rate and yield decreased, whereas growth rate and yield significantly increased due to biomass adaptation. A maximum polymer fraction in the biomass was therefore obtained at about 50% (on COD basis). As for the PHA composition, the copolymer poly(beta-hydroxybutyrate/beta-hydroxyvalerate) with 31% of hydroxyvalerate monomer was produced from the substrate mixture. Comparison of the tests with individual and mixed substrates seemed to indicate that, on removing the substrate mixture for copolymer production, propionic acid was fully utilized to produce propionylCoA, whereas the acetylCoA was fully provided by acetic and lactic acid. PMID:14966798

  8. Snamprogetti signs MTBE contracts

    SciTech Connect

    Alperowicz, N.

    1992-04-15

    Snamprogetti (Milan) will use a Russian-developed dehydrogenation process in a world-scale methyl tert-butyl ether (MTBE) plant it is to build at Arzew, Algeria for a previously announced joint venture of Sonatrach (Algiers), Total (Paris), and Ecofuel (Milan). The 600,000-m.t./year plant will be the first in the West to use the improved Snamprogetti-Yarsintez fluidized-bed dehydrogenation (FBD) technology proven on a demonstration plant at Yaroslavl, Russia. The process has also been selected for use in Oxyfuel Corp.`s 500,000-m.t./year MTBE plant near Beaumont, TX. Although the environmental permit is already in place, final agreement for this project has not yet been signed.

  9. Activated sludge mass reduction and biodegradability of the endogenous residues by digestion under different aerobic to anaerobic conditions: Comparison and modeling.

    PubMed

    Martínez-García, C G; Fall, C; Olguín, M T

    2016-03-01

    This study was performed to identify suitable conditions for the in-situ reduction of excess sludge production by intercalated digesters in recycle-activated sludge (RAS) flow. The objective was to compare and model biological sludge mass reduction and the biodegradation of endogenous residues (XP) by digestion under hypoxic, aerobic, anaerobic, and five intermittent-aeration conditions. A mathematical model based on the heterotrophic endogenous decay constant (bH) and including the biodegradation of XP was used to fit the long-term data from the digesters to identify and estimate the parameters. Both the bH constant (0.02-0.05 d(-1)) and the endogenous residue biodegradation constant (bP, 0.001-0.004 d(-1)) were determined across the different mediums. The digesters with intermittent aeration cycles of 12 h-12 h and 5 min-3 h (ON/OFF) were the fastest, compared to the aerobic reactor. The study provides a basis for rating RAS-digester volumes to avoid the accumulation of XP in aeration tanks. PMID:26720137

  10. Benzene and MTBE Sorption in Fine Grain Sediments

    NASA Astrophysics Data System (ADS)

    Leal-Bautista, R. M.; Lenczewski, M. E.

    2003-12-01

    The practice of adding methyl tert-butyl ether (MTBE) to gasoline started in the late 1970s and increased dramatically in the 1990s. MTBE first was added as a substitute for tetra-ethyl lead then later as a fuel oxygenate. Although the use of MTBE has resulted in significant reduction in air pollution, it has become a significant groundwater contaminant due to its high solubility in water, high environmental mobility, and low potential for biodegradation. A recent report (1999-2001) by the Metropolitan Water District of Southern California in collaboration with United State Geological Survey and the Oregon Health and Science University found that MTBE was the second most frequent detected volatile organic compound in groundwater. In Illinois, MTBE has been found in 26 of the 1,800 public water supplies. MTBE has also been blended in Mexico into two types of gasoline sold in the country by the state oil company (PEMEX) but is not monitored in groundwater at this time. Early research on MTBE considered it unable to adsorb to soils and sediments, however, by increasing the organic matter and decreasing the size of the grains (silts or clays) this may increase sorption. The objective of this study is to determine if fine grained materials have the potential for sorption of MTBE due to its high specific surface area (10-700 m 2/g) and potentially high organic matter (0.5-3.8%). The experiment consisted of sorption isotherms to glacial tills from DeKalb, Illinois and lacustrine clays from Chalco, Mexico. Experiments were performed with various concentrations of MTBE and benzene (10, 50, 100, 500 and 1000 ug/L) at 10° C and 25° C. Results showed a range of values for the distribution coefficient (Kd, linear model). At 10° C the Kd value for MTBE was 0.187 mL/g for lacustrine clay while the glacial loess had a value of 0.009 mL/g. The highest Kd values with MTBE were 0.2859 mL/g for organic rich lacustrine clays and 0.014 mL/g for glacial loess at 25° C. The highest

  11. BIODEGRADATION PROBABILITY PROGRAM (BIODEG)

    EPA Science Inventory

    The Biodegradation Probability Program (BIODEG) calculates the probability that a chemical under aerobic conditions with mixed cultures of microorganisms will biodegrade rapidly or slowly. It uses fragment constants developed using multiple linear and non-linear regressions and d...

  12. Biodegradation of vapor-phase toluene in unsaturated porous media: Column experiments.

    PubMed

    Khan, Ali M; Wick, Lukas Y; Harms, Hauke; Thullner, Martin

    2016-04-01

    Biodegradation of organic chemicals in the vapor phase of soils and vertical flow filters has gained attention as promising approach to clean up volatile organic compounds (VOC). The drivers of VOC biodegradation in unsaturated systems however still remain poorly understood. Here, we analyzed the processes controlling aerobic VOC biodegradation in a laboratory setup mimicking the unsaturated zone above a shallow aquifer. The setup allowed for diffusive vapor-phase transport and biodegradation of three VOC: non-deuterated and deuterated toluene as two compounds of highly differing biodegradability but (nearly) identical physical and chemical properties, and MTBE as (at the applied experimental conditions) non-biodegradable tracer and internal control. Our results showed for toluene an effective microbial degradation within centimeter VOC transport distances despite high gas-phase diffusivity. Degradation rates were controlled by the reactivity of the compounds while oxic conditions were found everywhere in the system. This confirms hypotheses that vadose zone biodegradation rates can be extremely high and are able to prevent the outgassing of VOC to the atmosphere within a centimeter range if compound properties and site conditions allow for sufficiently high degradation rates. PMID:26774779

  13. The paradoxes ofMTBE.

    PubMed

    Davis, J M; Farland, W H

    2001-06-01

    A widely used gasoline additive, methyl tertiary butyl ether (MTBE), has been controversial, in part because of concerns about potential inhalation health effects and more recently because of added concerns about water contamination. Although many of the issues related to MTBE have not been fully resolved, several apparent paradoxes can be discerned, including the fact that something intended to improve air quality is now seen as a threat to water quality. Among the lessons that can be derived from the MTBE experience is the value of a comprehensive understanding of the potential risk-benefit tradeoffs of different fuels and fuel additives. PMID:11353129

  14. Using DNA-Stable Isotope Probing to Identify MTBE- and TBA-Degrading Microorganisms in Contaminated Groundwater

    PubMed Central

    Key, Katherine C.; Sublette, Kerry L.; Duncan, Kathleen; Mackay, Douglas M.; Scow, Kate M.; Ogles, Dora

    2014-01-01

    Although the anaerobic biodegradation of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) has been documented in the laboratory and the field, knowledge of the microorganisms and mechanisms involved is still lacking. In this study, DNA-stable isotope probing (SIP) was used to identify microorganisms involved in anaerobic fuel oxygenate biodegradation in a sulfate-reducing MTBE and TBA plume. Microorganisms were collected in the field using Bio-Sep® beads amended with 13C5-MTBE, 13C1-MTBE (only methoxy carbon labeled), or13C4-TBA. 13C-DNA and 12C-DNA extracted from the Bio-Sep beads were cloned and 16S rRNA gene sequences were used to identify the indigenous microorganisms involved in degrading the methoxy group of MTBE and the tert-butyl group of MTBE and TBA. Results indicated that microorganisms were actively degrading 13C-labeled MTBE and TBA in situ and the 13C was incorporated into their DNA. Several sequences related to known MTBE- and TBA-degraders in the Burkholderiales and the Sphingomonadales orders were detected in all three13C clone libraries and were likely to be primary degraders at the site. Sequences related to sulfate-reducing bacteria and iron-reducers, such as Geobacter and Geothrix, were only detected in the clone libraries where MTBE and TBA were fully labeled with 13C, suggesting that they were involved in processing carbon from the tert-butyl group. Sequences similar to the Pseudomonas genus predominated in the clone library where only the methoxy carbon of MTBE was labeled with 13C. It is likely that members of this genus were secondary degraders cross-feeding on 13C-labeled metabolites such as acetate. PMID:25525320

  15. The potential for phytoremediation of MTBE.

    PubMed

    Rubin, E; Ramaswami, A

    2001-04-01

    This paper examines the potential for phytoremediation of MTBE, a gasoline additive that has become a prevalent and persistent groundwater pollutant, due to its' non-sorbing and non-reactive nature in water. A novel experimental design is developed to measure plant uptake and transpiration of MTBE from hydroponic systems, separating these processes from passive volatilization of the chemical. Plant uptake experiments indicate 30% reduction in MTBE mass in water over a 1-week period by small poplar saplings, at both high (1600 ppb) and low (300 ppb) MTBE concentrations. Active plant uptake of MTBE was approximately double that achieved by passive volatilization through a balsa wood control. MTBE was detected in biomass at the 100-ppb level, confirming passage of MTBE through the plant. A mass balance indicated that MTBE was largely untransformed during transport through the small poplar saplings to air. The high degree of MTBE removal achieved by small plants over a short period of time indicates great potential for successful phytoremediation of subsurface MTBE plumes using poplar trees. The fraction of MTBE removed from the hydroponic systems correlated well with volume of water transpired by the plants; the correlation enabled computation of the MTBE transpiration stream concentration factor of approximately 1, an important parameter for the design of engineered MTBE phytoremediation systems. PMID:11268857

  16. PERFORMANCE MONITORING OF ENHANCED IN-SITU BIOREMEDIATION OF MTBE IN GROUND WATER

    EPA Science Inventory

    The primary objective of the Biostimulation Technology Evaluation was to determine if enhanced biodegradation was occurring in a ground-water test plot to a sufficient degree to reduce intrinsic methyl tertiary butyl ether (MTBE) to the State of California's treatability criteria...

  17. TREATMENT OF MTBE USING FENTON'S REAGENT

    EPA Science Inventory

    This paper addresses the removal of MTBE from water, using Fenton's Reagent. Although complete mineralization of MTBE by Fenton's Reagent was not achieved, greater than 99% destruction of MTBE was realized. This was accomplished at a Fe+2:H2O2 ratio of 1:1 and one hour of contact...

  18. MTBE IS A LITTLE BIT OK?

    EPA Science Inventory

    Methyl tertiary butyl ether (MTBE) has been used as a gasoline additive to serve two major purposes. First, MTBE was used as an octane-enhancer to replace organic lead, beginning in about 1979. Beginning in about 1992, MTBE was also used as a fuel oxygenate additive to meet req...

  19. DEGRADATION OF MTBE INTERMEDIATES USING FENTON'S REAGENT

    EPA Science Inventory

    In a previous study, the chemical oxidation of MTBE at low concentrations in water using the Fenton's reagent (FR) was investigated. At certain reaction conditions the process achieved 99.99% degradation of MTBE but it did not result in complete MTBE mineralization. In the pres...

  20. Central Role of Dynamic Tidal Biofilms Dominated by Aerobic Hydrocarbonoclastic Bacteria and Diatoms in the Biodegradation of Hydrocarbons in Coastal Mudflats

    PubMed Central

    Coulon, Frédéric; Chronopoulou, Panagiota-Myrsini; Fahy, Anne; Païssé, Sandrine; Goñi-Urriza, Marisol; Peperzak, Louis; Acuña Alvarez, Laura; McKew, Boyd A.; Brussaard, Corina P. D.; Underwood, Graham J. C.; Timmis, Kenneth N.; Duran, Robert

    2012-01-01

    Mudflats and salt marshes are habitats at the interface of aquatic and terrestrial systems that provide valuable services to ecosystems. Therefore, it is important to determine how catastrophic incidents, such as oil spills, influence the microbial communities in sediment that are pivotal to the function of the ecosystem and to identify the oil-degrading microbes that mitigate damage to the ecosystem. In this study, an oil spill was simulated by use of a tidal chamber containing intact diatom-dominated sediment cores from a temperate mudflat. Changes in the composition of bacteria and diatoms from both the sediment and tidal biofilms that had detached from the sediment surface were monitored as a function of hydrocarbon removal. The hydrocarbon concentration in the upper 1.5 cm of sediments decreased by 78% over 21 days, with at least 60% being attributed to biodegradation. Most phylotypes were minimally perturbed by the addition of oil, but at day 21, there was a 10-fold increase in the amount of cyanobacteria in the oiled sediment. Throughout the experiment, phylotypes associated with the aerobic degradation of hydrocarbons, including polycyclic aromatic hydrocarbons (PAHs) (Cycloclasticus) and alkanes (Alcanivorax, Oleibacter, and Oceanospirillales strain ME113), substantively increased in oiled mesocosms, collectively representing 2% of the pyrosequences in the oiled sediments at day 21. Tidal biofilms from oiled cores at day 22, however, consisted mostly of phylotypes related to Alcanivorax borkumensis (49% of clones), Oceanospirillales strain ME113 (11% of clones), and diatoms (14% of clones). Thus, aerobic hydrocarbon biodegradation is most likely to be the main mechanism of attenuation of crude oil in the early weeks of an oil spill, with tidal biofilms representing zones of high hydrocarbon-degrading activity. PMID:22407688

  1. Comparison of Sampling Methods to Determine the Impact of Aerobic Biodegradation on Benzene Concentrations at UST Sites

    EPA Science Inventory

    This material will be interesting to regulators and contractors who collect samples of soil gas to estimate the potential for vapor intrusion of buildings. In the absence of biodegradation, transport of vapors through the unsaturated zone is expected to be by diffusion, and t...

  2. Betaine removal during thermo- and mesophilic aerobic batch biodegradation of beet molasses vinasse: influence of temperature and pH on the progress and efficiency of the process.

    PubMed

    Cibis, Edmund; Ryznar-Luty, Agnieszka; Krzywonos, Małgorzata; Lutosławski, Krzysztof; Miśkiewicz, Tadeusz

    2011-07-01

    The key issue in achieving a high extent of biodegradation of beet molasses vinasse is to establish the conditions for the assimilation of betaine, which is the main pollutant in this high-strength industrial effluent. In the present study, aerobic batch biodegradation was conducted over the temperature range of 27-63°C (step 9°C), at a pH of 6.5 and 8.0, using a mixed culture of bacteria of the genus Bacillus. Betaine was assimilated at 27-54°C and the pH of 8.0, as well as at 27-45°C and the pH of 6.5. The processes where betaine was assimilated produced a high BOD(5) removal, which exceeded 99.40% over the temperature range of 27-45°C at the pH of 8.0, as well as at 27°C and the pH of 6.5. Maximal COD removal (88.73%) was attained at 36°C and the pH of 6.5. The results indicate that the process can be applied on an industrial scale as the first step in the treatment of beet molasses vinasse. PMID:21367516

  3. The potential for hydrocarbon biodegradation and production of extracellular polymeric substances by aerobic bacteria isolated from a Brazilian petroleum reservoir.

    PubMed

    Vasconcellos, S P; Dellagnezze, B M; Wieland, A; Klock, J-H; Santos Neto, E V; Marsaioli, A J; Oliveira, V M; Michaelis, W

    2011-06-01

    Extracellular polymeric substances (EPS) can contribute to the cellular degradation of hydrocarbons and have a huge potential for application in biotechnological processes, such as bioremediation and microbial enhanced oil recovery (MEOR). Four bacterial strains from a Brazilian petroleum reservoir were investigated for EPS production, emulsification ability and biodegradation activity when hydrocarbons were supplied as substrates for microbial growth. Two strains of Bacillus species had the highest EPS production when phenanthrene and n-octadecane were offered as carbon sources, either individually or in a mixture. While Pseudomonas sp. and Dietzia sp., the other two evaluated strains, had the highest hydrocarbon biodegradation indices, EPS production was not detected. Low EPS production may not necessarily be indicative of an absence of emulsifier activity, as indicated by the results of a surface tension reduction assay and emulsification indices for the strain of Dietzia sp. The combined results gathered in this work suggest that a microbial consortium consisting of bacteria with interdependent metabolisms could thrive in petroleum reservoirs, thus overcoming the limitations imposed on each individual species by the harsh conditions found in such environments. PMID:25187151

  4. Reassessment of MTBE cancer potency considering modes of action for MTBE and its metabolites.

    PubMed

    Bogen, Kenneth T; Heilman, Jacqueline M

    2015-01-01

    A 1999 California state agency cancer potency (CP) evaluation of methyl tert-butyl ether (MTBE) assumed linear risk extrapolations from tumor data were plausible because of limited evidence that MTBE or its metabolites could damage DNA, and based such extrapolations on data from rat gavage and rat and mouse inhalation studies indicating elevated tumor rates in male rat kidney, male rat Leydig interstitial cells, and female rat leukemia/lymphomas. More recent data bearing on MTBE cancer potency include a rodent cancer bioassay of MTBE in drinking water; several new studies of MTBE genotoxicity; several similar evaluations of MTBE metabolites, formaldehyde, and tert-butyl alcohol or TBA; and updated evaluations of carcinogenic mode(s) of action (MOAs) of MTBE and MTBE metabolite's. The lymphoma/leukemia data used in the California assessment were recently declared unreliable by the U.S. Environmental Protection Agency (EPA). Updated characterizations of MTBE CP, and its uncertainty, are currently needed to address a variety of decision goals concerning historical and current MTBE contamination. To this end, an extensive review of data sets bearing on MTBE and metabolite genotoxicity, cytotoxicity, and tumorigenicity was applied to reassess MTBE CP and related uncertainty in view of MOA considerations. Adopting the traditional approach that cytotoxicity-driven cancer MOAs are inoperative at very low, non-cytotoxic dose levels, it was determined that MTBE most likely does not increase cancer risk unless chronic exposures induce target-tissue toxicity, including in sensitive individuals. However, the corresponding expected (or plausible upper bound) CP for MTBE conditional on a hypothetical linear (e.g., genotoxic) MOA was estimated to be ∼2 × 10(-5) (or 0.003) per mg MTBE per kg body weight per day for adults exposed chronically over a lifetime. Based on this conservative estimate of CP, if MTBE is carcinogenic to humans, it is among the weakest 10% of chemical

  5. Simulation of methyl tert-butyl ether (MTBE) transport to ground water from immobile sources of gasoline in the vadose zone

    USGS Publications Warehouse

    Lahvis, M.A.; Rehmann, L.C.

    1999-01-01

    The mathematical model, R-UNSAT, developed to simulate the transport of benzene and MTBE in representative sand and clay hydrogeologic systems was evaluated. The effects on groundwater were simulated for small, chronic-, and single-volume releases of gasoline trapped in unsaturated soil. Hydrocarbon biodegradation was simulated by using a dual Monod-type kinetics model that includes oxygen and the reactive constituents. MTBE was assumed to be non-reactive. For MTBE, infiltration had the greatest effect on transport to groundwater. Infiltration also affected mass losses of MTBE to the atmosphere, particularly, in fine-grained soils. Depth to groundwater and soil type primarily affected travel times of MTBE to groundwater, but could affect mass-loading rates to groundwater if infiltration is insignificant. For benzene, transport to groundwater was significant only if the depth to the water table was < 1 m or biodegradation was assumed to be negligible. Mass fluxed to groundwater were generally smaller for benzene than for MTBE by more than two orders of magnitude. Thus, water that recharges an aquifer beneath a spill can be enriched in MTBE relative to benzene when compared to the composition of water in equilibrium with gasoline.

  6. MTBE, TBA, and TAME attenuation in diverse hyporheic zones

    USGS Publications Warehouse

    Landmeyer, J.E.; Bradley, P.M.; Trego, D.A.; Hale, K.G.; Haas, J.E., II

    2010-01-01

    Groundwater contamination by fuel-related compounds such as the fuel oxygenates methyl tert-butyl ether (MTBE), tert-butyl alcohol (TBA), and tert-amyl methyl ether (TAME) presents a significant issue to managers and consumers of groundwater and surface water that receives groundwater discharge. Four sites were investigated on Long Island, New York, characterized by groundwater contaminated with gasoline and fuel oxygenates that ultimately discharge to fresh, brackish, or saline surface water. For each site, contaminated groundwater discharge zones were delineated using pore water geochemistry data from 15 feet (4.5 m) beneath the bottom of the surface water body in the hyporheic zone and seepage-meter tests were conducted to measure discharge rates. These data when combined indicate that MTBE, TBA, and TAME concentrations in groundwater discharge in a 5-foot (1.5-m) thick section of the hyporheic zone were attenuated between 34% and 95%, in contrast to immeasurable attenuation in the shallow aquifer during contaminant transport between 0.1 and 1.5 miles (0.1 to 2.4 km). The attenuation observed in the hyporheic zone occurred primarily by physical processes such as mixing of groundwater and surface water. Biodegradation also occurred as confirmed in laboratory microcosms by the mineralization of U- 14C-MTBE and U- 14C-TBA to 14CO2 and the novel biodegradation of U- 14C-TAME to 14CO2 under oxic and anoxic conditions. The implication of fuel oxygenate attenuation observed in diverse hyporheic zones suggests an assessment of the hyporheic zone attenuation potential (HZAP) merits inclusion as part of site assessment strategies associated with monitored or engineered attenuation. ?? 2009 National Ground Water Association.

  7. MTBE, TBA, and TAME attenuation in diverse hyporheic zones.

    PubMed

    Landmeyer, James E; Bradley, Paul M; Trego, Donald A; Hale, Kevin G; Haas, Joseph E

    2010-01-01

    Groundwater contamination by fuel-related compounds such as the fuel oxygenates methyl tert-butyl ether (MTBE), tert-butyl alcohol (TBA), and tert-amyl methyl ether (TAME) presents a significant issue to managers and consumers of groundwater and surface water that receives groundwater discharge. Four sites were investigated on Long Island, New York, characterized by groundwater contaminated with gasoline and fuel oxygenates that ultimately discharge to fresh, brackish, or saline surface water. For each site, contaminated groundwater discharge zones were delineated using pore water geochemistry data from 15 feet (4.5 m) beneath the bottom of the surface water body in the hyporheic zone and seepage-meter tests were conducted to measure discharge rates. These data when combined indicate that MTBE, TBA, and TAME concentrations in groundwater discharge in a 5-foot (1.5-m) thick section of the hyporheic zone were attenuated between 34% and 95%, in contrast to immeasurable attenuation in the shallow aquifer during contaminant transport between 0.1 and 1.5 miles (0.1 to 2.4 km). The attenuation observed in the hyporheic zone occurred primarily by physical processes such as mixing of groundwater and surface water. Biodegradation also occurred as confirmed in laboratory microcosms by the mineralization of U- (14)C-MTBE and U-(14)C-TBA to (14)CO(2) and the novel biodegradation of U- (14)C-TAME to (14)CO(2) under oxic and anoxic conditions. The implication of fuel oxygenate attenuation observed in diverse hyporheic zones suggests an assessment of the hyporheic zone attenuation potential (HZAP) merits inclusion as part of site assessment strategies associated with monitored or engineered attenuation. PMID:19664047

  8. Metaproteomics reveals major microbial players and their biodegradation functions in a large-scale aerobic composting plant.

    PubMed

    Liu, Dongming; Li, Mingxiao; Xi, Beidou; Zhao, Yue; Wei, Zimin; Song, Caihong; Zhu, Chaowei

    2015-11-01

    Composting is an appropriate management alternative for municipal solid waste; however, our knowledge about the microbial regulation of this process is still scare. We employed metaproteomics to elucidate the main biodegradation pathways in municipal solid waste composting system across the main phases in a large-scale composting plant. The investigation of microbial succession revealed that Bacillales, Actinobacteria and Saccharomyces increased significantly with respect to abundance in composting process. The key microbiologic population for cellulose degradation in different composting stages was different. Fungi were found to be the main producers of cellulase in earlier phase. However, the cellulolytic fungal communities were gradually replaced by a purely bacterial one in active phase, which did not support the concept that the thermophilic fungi are active through the thermophilic phase. The effective decomposition of cellulose required the synergy between bacteria and fungi in the curing phase. PMID:25989417

  9. Metaproteomics reveals major microbial players and their biodegradation functions in a large-scale aerobic composting plant

    PubMed Central

    Liu, Dongming; Li, Mingxiao; Xi, Beidou; Zhao, Yue; Wei, Zimin; Song, Caihong; Zhu, Chaowei

    2015-01-01

    Composting is an appropriate management alternative for municipal solid waste; however, our knowledge about the microbial regulation of this process is still scare. We employed metaproteomics to elucidate the main biodegradation pathways in municipal solid waste composting system across the main phases in a large-scale composting plant. The investigation of microbial succession revealed that Bacillales, Actinobacteria and Saccharomyces increased significantly with respect to abundance in composting process. The key microbiologic population for cellulose degradation in different composting stages was different. Fungi were found to be the main producers of cellulase in earlier phase. However, the cellulolytic fungal communities were gradually replaced by a purely bacterial one in active phase, which did not support the concept that the thermophilic fungi are active through the thermophilic phase. The effective decomposition of cellulose required the synergy between bacteria and fungi in the curing phase. PMID:25989417

  10. Biodegradation and detoxification of melanoidin from distillery effluent using an aerobic bacterial strain SAG5 of Alcaligenes faecalis.

    PubMed

    Santal, Anita Rani; Singh, N P; Saharan, Baljeet Singh

    2011-10-15

    Distillery effluent retains very dark brown color even after anaerobic treatment due to presence of various water soluble, recalcitrant and coloring compounds mainly melanoidins. In laboratory conditions, melanoidin decolorizing bacteria was isolated and optimized the cultural conditions at various incubation temperatures, pH, carbon sources, nitrogen sources and combined effect of both carbon and nitrogen sources. The optimum decolorization (72.6 ± 0.56%) of melanoidins was achieved at pH 7.5 and temperature 37 °C on 5th day of cultivation. The toxicity evaluation with mung bean (Vigna radiata) revealed that the raw distillery effluent was environmentally highly toxic as compared to biologically treated distillery effluent, which indicated that the effluent after bacterial treatment is environmentally safe. This proves to be novel biological treatment technique for biodegradation and detoxification of melanoidin from distillery effluent using the bacterial strain SAG(5). PMID:21880418

  11. Methyl tert-butyl ether biodegradation by indigenous aquifer microorganisms under natural and artificial oxic conditions

    USGS Publications Warehouse

    Landmeyer, J.E.; Chapelle, F.H.; Herlong, H.H.; Bradley, P.M.

    2001-01-01

    Microbial communities indigenous to a shallow groundwater system near Beaufort, SC, degraded milligram per liter concentrations of methyl tert-butyl ether (MTBE) under natural and artificial oxic conditions. Significant MTBE biodegradation was observed where anoxic, MTBE-contaminated groundwater discharged to a concrete-lined ditch. In the anoxic groundwater adjacent to the ditch, concentrations of MTBE were > 1 mg/L. Where groundwater discharge occurs, dissolved oxygen (DO) concentrations beneath the ditch exceeded 1.0 mg/L to a depth of 1.5 m, and MTBE concentrations decreased to <1 ??g/L prior to discharge. MTBE mass flux calculations indicate that 96% of MTBE mass loss occurs in the relatively small oxic zone prior to discharge. Samples of a natural microbial biofilm present in the oxic zone beneath the ditch completely degraded [U-14C]MTBE to [14C]CO2 in laboratory liquid culture studies, with no accumulation of intermediate compounds. Upgradient of the ditch in the anoxic, MTBE and BTEX-contaminated aquifer, addition of a soluble oxygen release compound resulted in oxic conditions and rapid MTBE biodegradation by indigenous microorganisms. In an observation well located closest to the oxygen addition area, DO concentrations increased from 0.4 to 12 mg/L in <60 days and MTBE concentrations decreased from 20 to 3 mg/L. In the same time period at a downgradient observation well, DO increased from <0.2 to 2 mg/L and MTBE concentrations decreased from 30 to <5 mg/L. These results indicate that microorganisms indigenous to the groundwater system at this site can degrade milligram per liter concentrations of MTBE under natural and artificial oxic conditions.

  12. Methyl tert-butyl ether biodegradation by indigenous aquifer microorganisms under natural and artificial oxic conditions.

    PubMed

    Landmeyer, J E; Chapelle, F H; Herlong, H H; Bradley, P M

    2001-03-15

    Microbial communities indigenous to a shallow groundwater system near Beaufort, SC, degraded milligram per liter concentrations of methyl tert-butyl ether (MTBE) under natural and artificial oxic conditions. Significant MTBE biodegradation was observed where anoxic, MTBE-contaminated groundwater discharged to a concrete-lined ditch. In the anoxic groundwater adjacent to the ditch, concentrations of MTBE were > 1 mg/L. Where groundwater discharge occurs, dissolved oxygen (DO) concentrations beneath the ditch exceeded 1.0 mg/Lto a depth of 1.5 m, and MTBE concentrations decreased to <1 microg/L prior to discharge. MTBE mass flux calculations indicate that 96% of MTBE mass loss occurs in the relatively small oxic zone prior to discharge. Samples of a natural microbial biofilm present in the oxic zone beneath the ditch completely degraded [U-14C]MTBE to [14C]CO2 in laboratory liquid culture studies, with no accumulation of intermediate compounds. Upgradient of the ditch in the anoxic, MTBE- and BTEX-contaminated aquifer, addition of a soluble oxygen release compound resulted in oxic conditions and rapid MTBE biodegradation by indigenous microorganisms. In an observation well located closest to the oxygen addition area, DO concentrations increased from 0.4 to 12 mg/L in <60 days and MTBE concentrations decreased from 20 to 3 mg/L. In the same time period at a downgradient observation well, DO increased from <0.2 to 2 mg/L and MTBE concentrations decreased from 30 to <5 mg/L. These results indicate that microorganisms indigenous to the groundwater system at this site can degrade milligram per liter concentrations of MTBE under natural and artificial oxic conditions. PMID:11347923

  13. ENVIROGEN PROPANE BIOSTIMULATION TECHNOLOGY FOR THE IN-SITU TREATMENT OF MTBE-CONTAMINATED GROUND WATER INNOVATIVE TECHNOLOGY EVALUATION REPORT

    EPA Science Inventory

    The primary objective of the Biostimulation Technology Evaluation was to determine if biodegradation was occurring in a ground-water Test Plot to a sufficient degree to reduce intrinsic MTBE to the State of California's treatability criteria of 5 mg/L or below. The evaluation wa...

  14. Systems Characterization of Temperature, Ph and Electrical Conductivity in Aerobic Biodegradation of Wheat Biomass at Differing Mixing Rates

    NASA Technical Reports Server (NTRS)

    Calhoun, M.; Trotman, A.; Aglan, H.

    1998-01-01

    The purpose of this preliminary study is to observe and relate the rate of mixing to pH and electrical conductivity in an aerobic, continuously stirred bioreactor. The objective is to use data collected from successive experiments as a means of a system characterization. Tests were conducted to obtain these data using a continuously stirred 20 L Cytostir glass reaction vessel as a bioreactor operated without built-in temperature or pH control. The tests were conducted on the lab bench at ambient temperatures. The substrate in the bioreactor was ground wheat biomass obtained from the Biomass Production Chamber at NASA Kennedy Space Center. In this study, the data reflect characteristics of the native (uninoculated) systems as well as inoculated systems. In the native systems, it was found that pi levels became stable after approximately 2 to 3 days. The electrical conductivity levels for the native systems tended to decrease over time. In contrast, ion activity was increased after the introduction of bacteria into the system. This could be correlated with the release of nutrients, due to the activity of the bacteria. Also, there were slight increases in pH in the inoculated system, a result which is expected for a system with no active pr controls. The data will be used to test a mathematical model in an automated system.

  15. MICROCOSM STUDY OF ANAEROBIC BIODEGRDATOIN OF MTBE

    EPA Science Inventory

    The relative concentrations TBA to MTBE in ground water samples from a gasoline spill site in Orange County, California suggested that MTBE was being transformed to TBA. In some of the most heavily contaminated wells, the concentration of TBA was higher than the concentration of...

  16. Status and Impacts of State MTBE Bans

    EIA Publications

    2003-01-01

    This paper describes legislation passed in 16 states banning or restricting the use of methyl tertiary butyl ether (MTBE) in gasoline. Analysis of the status and impact of these state MTBE bans is provided concerning the supply and potential price changes of gasoline.

  17. COSTS TO REMEDIATE MTBE-CONTAMINATED SITES

    EPA Science Inventory

    The extensive contamination of methyl tert-butyl ether (MTBE) in ground water has introduced concerns about the increased cost of remediation of MTBE releases compared to sites with BTEX only contamination. In an attempt to evaluate these costs, cost information for 311 sites wa...

  18. Genes involved in the methyl tert-butyl ether (MTBE) metabolic pathway of Mycobacterium austroafricanum IFP 2012.

    PubMed

    Lopes Ferreira, Nicolas; Labbé, Diane; Monot, Frédéric; Fayolle-Guichard, Françoise; Greer, Charles W

    2006-05-01

    Methyl tert-butyl ether (MTBE) is a persistent pollutant of surface and groundwater, and the reasons for its low biodegradability are poorly documented. Using one of the rare bacterial strains able to grow in the presence of MTBE, Mycobacterium austroafricanum IFP 2012, the protein profiles of crude extracts after growth in the presence of MTBE and glucose were compared by SDS-PAGE. Ten proteins with molecular masses of 67, 64, 63, 55, 50, 27, 24, 17, 14 and 11 kDa were induced after growth in the presence of MTBE. Partial amino acid sequences of N-terminal and internal peptide fragments of the 64 kDa protein were used to design degenerate oligonucleotide primers to amplify total DNA by PCR, yielding a DNA fragment that was used as a probe for cloning. A two-step cloning procedure was performed to obtain a 10 327 bp genomic DNA fragment containing seven ORFs, including a putative regulator, mpdR, and four genes, mpdC, orf1, mpdB and orf2, in the same cluster. The MpdB protein (64 kDa) was related to a flavoprotein of the glucose-methanol-choline oxidoreductase family, and the MpdC protein (55 kDa) showed a high similarity with NAD(P) aldehyde dehydrogenases. Heterologous expression of these gene products was performed in Mycobacterium smegmatis mc2 155. The recombinant strain was able to degrade an intermediate of MTBE biodegradation, 2-methyl 1,2-propanediol, to hydroxyisobutyric acid. This is believed to be the first report of the cloning and characterization of a cluster of genes specifically involved in the MTBE biodegradation pathway of M. austroafricanum IFP 2012. PMID:16622053

  19. Comparison of biodegradation of low-weight hydroentangled raw cotton nonwoven fabric and that of commonly used disposable nonwoven fabrics in the aerobic Captina silt loam soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The increasing use of disposable nonwovens made of petroleum-based materials generates a large amount of non-biodegradable, solid waste in the environment. As an effort to enhance the usage of biodegradable cotton in nonwovens, this study analyzed the biodegradability of mechanically pre-cleaned gr...

  20. [Research advances in aerobic denitrifiers].

    PubMed

    Wang, Wei; Cai, Zu-cong; Zhong, Wen-hui; Wang, Guo-xiang

    2007-11-01

    This paper reviewed the varieties and characteristics of aerobic denitrifiers, their action mechanisms, and the factors affecting aerobic denitrification. Aerobic denitrifiers mainly include Pseudomonas, Alcaligenes, Paracoccus and Bacillus, which are either aerobic or facultative aerobic, and heterotrophic. They can denitrify under aerobic conditions, with the main product being N2O. They can also convert NH4+ -N to gas product. The nitrate reductase which catalyzes the denitrification is periplasmic nitrate reductase rather than membrane-bound nitrate reductase. Dissolved oxygen concentration and C/N ratio are the main factors affecting aerobic denitrification. The main methods for screening aerobic denitrifiers, such as intermittent aeration and selected culture, were also introduced. The research advances in the application of aerobic denitrifiers in aquaculture, waste water processing, and bio-degradation of organic pollutants, as well as the contributions of aerobic denitrifiers to soil nitrogen emission were summarized. PMID:18260473

  1. Misconceptions concerning the behavior, fate and transport of the fuel oxygenates TBA and MTBE

    NASA Astrophysics Data System (ADS)

    Woodward, R.; Sloan, R.

    2003-04-01

    The release of gasoline from underground storage tanks and the subsequent appearance of dissolved constituents in drinking water has focused attention on the use of MTBE in reformulated fuels. Natural biodegradation of MTBE in soil, photo-oxidation in the atmosphere or chemical oxidation during remediation of gasoline releases can produce the intermediate tertiary butyl alcohol (TBA). TBA is also a fuel oxygenate and can be found as a co-product in MTBE synthesized from methanol and TBA. Because the physical properties of ethers and alcohols differ somewhat from the predominant hydrocarbon compounds in gasoline, misconceptions have developed about the behavior of fuel oxygenates in storage and in the subsurface. Critical review of several misconceptions about MTBE and TBA in gasoline reveals the concepts were conceived to rationalize early field observations and/or incomplete data sets. Closer scrutiny, in light of recent laboratory investigations, field data, case studies and world literature, clarifies these misconceptions and assumptions about the behavior of ether oxygenates and their degradation products in the environment. Commonly held misconceptions focus on four general areas of fuel and fuel oxygenate management: storage/dispensing, hydrology, remediation, and health effects. Storage/dispensing misconceptions address materials stability to ethers and alcohols in fuel and the environmental forensics of fuel systems failure. Groundwater and hydrology misconceptions deal with plume dynamics and the impact of fuel on drinking water resources. Remediation misconceptions focus on the performance of traditional hydrocarbon remediation technologies, recent developments in biodegradation and natural attenuation, drivers of remedial design and remediation costs. Health effects misconceptions address both acute and chronic exposure risk evaluations by national and international health agencies. Generally MTBE and TBA are manageable by the same processes and

  2. Grey water biodegradability.

    PubMed

    Ghunmi, Lina Abu; Zeeman, Grietje; Fayyad, Manar; van Lier, Jules B

    2011-02-01

    Knowing the biodegradability characteristics of grey water constituents is imperative for a proper design and operation of a biological treatment system of grey water. This study characterizes the different COD fractions of dormitory grey water and investigates the effect of applying different conditions in the biodegradation test. The maximum aerobic and anaerobic biodegradability and conversion rate for the different COD fractions is determined. The results show that, on average, dormitory grey water COD fractions are 28% suspended, 32% colloidal and 40% dissolved. The studied factors incubation time, inoculum addition and temperature are influencing the determined biodegradability. The maximum biodegradability and biodegradation rate differ between different COD fractions, viz. COD(ss), COD(col) and COD(diss). The dissolved COD fraction is characterised by the lowest degradation rate, both for anaerobic and aerobic conditions. The maximum biodegradability for aerobic and anaerobic conditions is 86 and 70% respectively, whereas the first order conversion rate constant, k₂₀, is 0.119 and 0.005 day⁻¹, respectively. The anaerobic and aerobic conversion rates in relation to temperature can be described by the Arrhenius relation, with temperature coefficients of 1.069 and 1.099, respectively. PMID:20658309

  3. Factors influencing biological treatment of MTBE contaminated ground water

    SciTech Connect

    Stringfellow, William T.; Hines Jr., Robert D.; Cockrum, Dirk K.; Kilkenny, Scott T.

    2001-09-14

    Methyl tert-butyl ether (MTBE) contamination has complicated the remediation of gasoline contaminated sites. Many sites are using biological processes for ground water treatment and would like to apply the same technology to MTBE. However, the efficiency and reliability of MTBE biological treatment is not well documented. The objective of this study was to examine the operational and environmental variables influencing MTBE biotreatment. A fluidized bed reactor was installed at a fuel transfer station and used to treat ground water contaminated with MTBE and gasoline hydrocarbons. A complete set of chemical and operational data was collected during this study and a statistical approach was used to determine what variables were influencing MTBE treatment efficiency. It was found that MTBE treatment was more sensitive to up-set than gasoline hydrocarbon treatment. Events, such as excess iron accumulation, inhibited MTBE treatment, but not hydrocarbon treatment. Multiple regression analysis identified biomass accumulation and temperature as the most important variables controlling the efficiency of MTBE treatment. The influent concentration and loading of hydrocarbons, but not MTBE, also impacted MTBE treatment efficiency. The results of this study suggest guidelines for improving MTBE treatment. Long cell retention times in the reactor are necessary for maintaining MTBE treatment. The onset of nitrification only occurs when long cell retention times have been reached and can be used as an indicator in fixed film reactors that conditions favorable to MTBE treatment exist. Conversely, if the reactor can not nitrify, it is unlikely to have stable MTBE treatment.

  4. MTBE: Wild card in groundwater cleanup

    SciTech Connect

    Koenigsberg, S.

    1997-11-01

    Subsurface releases of the gasoline oxygenate, methyl tertiary butyl ether (MTBE) seriously compromise the remediation and closure of properties that have ground water contaminated with BTEX and other conventional fuel hydrocarbon components. Although a manageable protocal for BTEX remediation is being set up, the MTBE problem continues to be difficult. This article discusses a new magnesium peroxide compound which could be part of the solution. Covered topics include oxygen release compound (ORC) enhance bioremediation and the role of oxygen and ORC in MTBE remediation. 1 fig.

  5. MTBE: The headache of cleaner air

    SciTech Connect

    Kneiss, J.

    1995-07-01

    Gasoline with methyl tertiary butyl ether (MTBE) has been sold in the United States since 1979, when it was added to fuels as an octane enhancer after lead was phased out of motor fuels. Recently it has been introduced as a means of reducing carbon monoxide emissions during the winter months in targeted US cities. However, there is concern over health complaints including headaches, dizziness and nausea from residents of some areas. These reports have launched an era of assidious research by scientists and public health officials across the country to learn more about MTBE`s short-term and long-term, and possibly carcinogenic, health effects. New research should help weigh the risk of MTBE as a possible carcinogen and the effectiveness of MTBE-blended fuels in reducing carbon monoxide levels. The question is whether, in minimizing one risk, is another risk - however small - being introduced?

  6. Evaluation of integrated anaerobic/aerobic fixed-bed sequencing batch biofilm reactor for decolorization and biodegradation of azo dye acid red 18: comparison of using two types of packing media.

    PubMed

    Hosseini Koupaie, E; Alavi Moghaddam, M R; Hashemi, S H

    2013-01-01

    Two integrated anaerobic/aerobic fixed-bed sequencing batch biofilm reactor (FB-SBBR) were operated to evaluate decolorization and biodegradation of azo dye Acid Red 18 (AR18). Volcanic pumice stones and a type of plastic media made of polyethylene were used as packing media in FB-SBBR1 and FB-SBBR2, respectively. Decolorization of AR18 in both reactors followed first-order kinetic with respect to dye concentration. More than 63.7% and 71.3% of anaerobically formed 1-naphthylamine-4-sulfonate (1N-4S), as one of the main sulfonated aromatic constituents of AR18 was removed during the aerobic reaction phase in FB-SBBR1 and FB-SBBR2, respectively. Based on statistical analysis, performance of FB-SBBR2 in terms of COD removal as well as biodegradation of 1N-4S was significantly higher than that of FB-SBBR1. Spherical and rod shaped bacteria were the dominant species of bacteria in the biofilm grown on the pumice stones surfaces, while, the biofilm grown on surfaces of the polyethylene media had a fluffy structure. PMID:23138064

  7. FENTON-DRIVEN CHEMICAL REGENERATION OF MTBE-SPENT GAC

    EPA Science Inventory

    Methyl tert-butyl ether (MTBE)-spent granular activated carbon (GAC) was chemically regenerated utilizing the Fenton mechanism. Two successive GAC regeneration cycles were performed involving iterative adsorption and oxidation processes: MTBE was adsorbed to the GAC, oxidized, r...

  8. Occurrence of the gasoline oxygenate MTBE and BTEX compounds in urban stormwater in the United States, 1991-95

    USGS Publications Warehouse

    Delzer, Gregory C.; Zogorski, John S.; Lopes, T.J.; Bosshart, R.L.

    1996-01-01

    Methyl tert-butyl ether (MTBE) is a gasoline oxygenate. Oxygenates such as MTBE, when added to gasoline, increase the gasoline's oxygen level and decrease vehicular carbon monoxide emissions and ozone levels in the atmosphere. MTBE disperses rapidly in water, was the second most frequently detected volatile organic compound (VOC) in a study of shallow urban ground water, and is less biodegradable than common gasoline compounds, such as benzene, toluene, ethylbenzene, and total xylene (BTEX). Urban stormwater is a possible source of MTBE found in shallow ground water. The U.S. Geological Survey (USGS) sampled stormwater in 16 cities and metropolitan areas that are required to obtain permits to discharge stormwater from their municipal storm-sewer system into surface water. Concentrations of 62 VOCs, including MTBE and BTEX compounds, were measured in 592 stormwater samples collected in these cities and metropolitan areas from 1991 through 1995. Concentration data for MTBE and BTEX compounds in stormwater were compiled and analyzed, and the findings are summarized in this report. This effort was part of an interagency assessment of the scientific basis and effectiveness of the Nation's oxygenated fuel program and was coordinated by the Office of Science and Technology Policy, Executive Office of the President. MTBE was the seventh most frequently detected VOC in urban stormwater, following toluene, total xylene, chloroform, total trimethylbenzene, tetrachloroethene, and naphthalene. MTBE was detected in 6.9 percentmg (41 of 592) of stormwater samples collected. When detected, concentrations of MTBE ranged from 0.2 to 8.7 micrograms per liter (ug/L), with a median of 1.5 ug/L. All detections of MTBE were less than the lower limit of the U.S. Environmental Protection Agency (EPA) draft lifetime health advisory (20 ug/L) for drinking water. Eighty- three percent of all detections of MTBE in stormwater were in samples collected during the October through March season of

  9. FATE AND TRANSPORT OF MTBE AND OTHER GASOLINE COMPONENTS

    EPA Science Inventory

    This book chapter reviews the processes and interactions that control the transport and fate of MTBE and TBA in the subsurface. It describes the transport and fate of vapors of MTBE in the unsaturated zone, the partitioning of MTBE from gasoline spills directly into water, and t...

  10. Comparison of biostimulation versus bioaugmentation with bacterial strain PM1 for treatment of groundwater contaminated with methyl tertiary butyl ether (MTBE).

    PubMed

    Smith, Amanda E; Hristova, Krassimira; Wood, Isaac; Mackay, Doug M; Lory, Ernie; Lorenzana, Dale; Scow, Kate M

    2005-03-01

    Widespread contamination of groundwater by methyl tertiary butyl ether (MTBE) has triggered the exploration of different technologies for in situ removal of the pollutant, including biostimulation of naturally occurring microbial communities or bioaugmentation with specific microbial strains known to biodegrade the oxygenate. After laboratory studies revealed that bacterial strain PM1 rapidly and completely biodegraded MTBE in groundwater sediments, the organism was tested in an in situ field study at Port Hueneme Naval Construction Battalion Center in Oxnard, California. Two pilot test plots (A and B) in groundwater located down-gradient from an MTBE source were intermittently sparged with pure oxygen. Plot B was also inoculated with strain PM1. MTBE concentrations up-gradient from plots A and B initially varied temporally from 1.5 to 6 mg MTBE/L. Six months after treatment began, MTBE concentrations in monitoring wells down-gradient from the injection bed decreased substantially in the shallow zone of the groundwater in plots A and B, thus even in the absence of the inoculated strain PM1. In the deeper zone, downstream MTBE concentrations also decreased in plot A and to a lesser extent in plot B. Difficulties in delivery of oxygen to the deeper zone of plot B, evidenced by low dissolved oxygen concentrations, were likely responsible for low rates of MTBE removal at that location. We measured the survival and movement of strain PM1 in groundwater samples using two methods for detection of DNA sequences specific to strain PM1: TaqMan quantitative polymerase chain reaction, and internal transcribed spacer region analysis. A naturally occurring bacterial strain with > 99% 16S rDNA sequence similarity to strain PM1 was detected in groundwater collected at various locations at Port Hueneme, including outside the plots where the organism was inoculated. Addition of oxygen to naturally occurring microbial populations was sufficient to stimulate MTBE removal at this site

  11. Successful treatment of an MTBE-impacted aquifer using a bioreactor self-colonized by native aquifer bacteria

    PubMed Central

    Hicks, Kristin A.; Nickelsen, Michael G.; Boyle, Susan L.; Baker, Jeffrey M.; Tornatore, Paul M.; Hristova, Krassimira R.; Scow, Kate M.

    2014-01-01

    A field-scale fixed bed bioreactor was used to successfully treat an MTBE-contaminated aquifer in North Hollywood, CA without requiring inoculation with introduced bacteria. Native bacteria from the MTBE-impacted aquifer rapidly colonized the bioreactor, entering the bioreactor in the contaminated groundwater pumped from the site, and biodegraded MTBE with greater than 99 % removal efficiency. DNA sequencing of the 16S rRNA gene identified MTBE-degrading bacteria Methylibium petroleiphilum in the bioreactor. Quantitative PCR showed M. petroleiphilum enriched by three orders of magnitude in the bioreactor above densities pre-existing in the groundwater. Because treatment was carried out by indigenous rather than introduced organisms, regulatory approval was obtained for implementation of a full-scale bioreactor to continue treatment of the aquifer. In addition, after confirmation of MTBE removal in the bioreactor to below maximum contaminant limit levels (MCL; MTBE = 5 μg L−1), treated water was approved for reinjection back into the aquifer rather than requiring discharge to a water treatment system. This is the first treatment system in California to be approved for reinjection of biologically treated effluent into a drinking water aquifer. This study demonstrated the potential for using native microbial communities already present in the aquifer as an inoculum for ex-situ bioreactors, circumventing the need to establish non-native, non-acclimated and potentially costly inoculants. Understanding and harnessing the metabolic potential of native organisms circumvents some of the issues associated with introducing non-native organisms into drinking water aquifers, and can provide a low-cost and efficient remediation technology that can streamline future bioremediation approval processes. PMID:23613160

  12. MTBE concentration profiles near MTBE manufacturing plant: modeling approach and modeling uncertainty.

    PubMed

    Chang, Ken-Hui; Chen, Chien-Hung

    2009-06-01

    The methyl tert-butyl ether (MTBE) concentration profiles near a MTBE manufacturing plant were monitored on two occasions. The US EPA's atmospheric dispersion model (industrial source complex short-term) was used to model the ambient MTBE levels with the input of local meteorological data as well as MTBE emissions from the plant. The measured ambient MTBE concentrations range from 6 to 76 microgm(-3) with the average value about 33 microgm(-3). These values are similar to those values reported in ambient air in the vicinity of service stations of 4-12 microgm(-3) and tollbooths at a highway of 10-22 microgm(-3), but lower than those values reported in ambient air near gas stations of 50-690 microgm(-3), and higher than those values reported in atmospheric of 0.9-3.0 microgm(-3). Since the model has not been validated for the simulated MTBE profiles, there exist differences between the observed and mode-predicted data. The sensitivity and uncertainty of model parameters were then analyzed. The effects of wind direction, wind velocity and atmospheric stability are discussed in terms of their impact on model sensitivity/uncertainty. PMID:19342074

  13. Eliminating MTBE in Gasoline in 2006

    EIA Publications

    2006-01-01

    A review of the market implications resulting from the rapid change from methyl tertiary butyl ether (MTBE) to ethanol-blended reformulated gasoline (RFG) on the East Coast and in Texas. Strains in ethanol supply and distribution will increase the potential for price volatility in these regions this summer.

  14. MTBE REMOVAL FROM DRINKING WATER - PHASE I

    EPA Science Inventory

    The 1990 Federal Clean Air Act mandated the incorporation of oxygenates into gasoline in ozone and carbon monoxide nonattainment areas. Methyl tertiary butyl ether (MTBE) is the oxygenate of choice due to economic and supply considerations. Despite federal and state prog...

  15. DESIGN OF A MTBE REMEDIATION TECHNOLOGY EVALUATION

    EPA Science Inventory

    This study examines the intrinsic variability of dissolved MTBE concentrations in ground water during the course of a pilot-scale bioremedial technology trial in Port Hueneme, California. A pre-trial natural gradient tracer experiment using bromide was conducted in an anaerobic t...

  16. DEGRADATION OF MTBE BY PSYCHROPHILIC BACTERIA

    EPA Science Inventory

    MTBE, a gasoline additive, is a persistent and foul tasting contaminant that is more mobile in groundwater than BTEX (benzene, toluene, ethylbenzene, xylenes). It is turning up at many American crossroads. The objective of this well controlled study was to determine if biologic...

  17. Methyl tert-butyl ether (MTBE)

    Integrated Risk Information System (IRIS)

    Methyl tert - butyl ether ( MTBE ) ; CASRN 1634 - 04 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments f

  18. NEW HYPOTHESES FOR MTBE COMBUSTION PRODUCTS

    EPA Science Inventory

    A 1997 AWMA paper (97-TA34.02) presented evidence linking explosive increases in asthma and other conditions to the introduction of gasoline oxygenated with methyl tertiary butyl ether (MTBE) in Philadelphia and other places. In the winter of 92-93 the state of Alaska withdrew f...

  19. Occurrence and temporal variability of methyl tert-butyl ether (MTBE) and other volatile organic compounds in select sources of drinking water : results of the focused survey

    USGS Publications Warehouse

    Delzer, Gregory C.; Ivahnenko, Tamara

    2003-01-01

    The large-scale use of the gasoline oxygenate methyl tert-butyl ether (MTBE), and its high solubility, low soil adsorption, and low biodegradability, has resulted in its detection in ground water and surface water in many places throughout the United States. Studies by numerous researchers, as well as many State and local environmental agencies, have discovered high levels of MTBE in soils and ground water at leaking underground gasoline-storage-tank sites and frequent occurrence of low to intermediate levels of MTBE in reservoirs used for both public water supply and recreational boating.In response to these findings, the American Water Works Association Research Foundation sponsored an investigation of MTBE and other volatile organic compounds (VOCs) in the Nation?s sources of drinking water. The goal of the investigation was to provide additional information on the frequency of occurrence, concentration, and temporal variability of MTBE and other VOCs in source water used by community water systems (CWSs). The investigation was completed in two stages: (1) reviews of available literature and (2) the collection of new data. Two surveys were associated with the collection of new data. The first, termed the Random Survey, employed a statistically stratified design for sampling source water from 954 randomly selected CWSs. The second, which is the focus of this report, is termed the Focused Survey, which included samples collected from 134 CWS source waters, including ground water, reservoirs, lakes, rivers, and streams, that were suspected or known to contain MTBE. The general intent of the Focused Survey was to compare results with the Random Survey and provide an improved understanding of the occurrence, concentration, temporal variability, and anthropogenic factors associated with frequently detected VOCs. Each sample collected was analyzed for 66 VOCs, including MTBE and three other ether gasoline oxygenates (hereafter termed gasoline oxygenates). As part of

  20. Biodegradation of Reactive blue 13 in a two-stage anaerobic/aerobic fluidized beds system with a Pseudomonas sp. isolate.

    PubMed

    Lin, Jun; Zhang, Xingwang; Li, Zhongjian; Lei, Lecheng

    2010-01-01

    Pseudomonas sp. strain L1 capable of degrading the azo textile dye Reactive blue 13, was isolated from activated sludge in a sequencing batch reactor. A continuous two-stage anaerobic/aerobic biological fluidized bed system was used to decolorize and mineralize Reactive blue 13. The key factors affecting decolorization were investigated and the efficiency of degradation was also optimized. An overall color removal of 83.2% and COD removal of 90.7% was achieved at pH 7, a residence time of 70 h and a glucose concentration of 2 g/L, HRT=70 h and C(glucose)=2000 mg/L. Oxygen was contributing to blocking the azo bond cleavage. Consequently, decolorization occurred in the anaerobic reactor while partial mineralization was achieved in the aerobic reactor. A possible degradation pathway based on the analysis of intermediates and involving azoreduction, desulfonation, deamination and further oxidation reactions is presented. PMID:19713103

  1. ENHANCED BIODEGRADATION THROUGH IN-SITU AERATION

    EPA Science Inventory

    This presentation provided an overview of enhanced aerobic bioremediation using in-situ aeration or venting. The following topics were covered: (1) Basic discussion on biodegradation and respiration testing; (2) Basic discussion on volatilization, rate-limited mass transport, an...

  2. Removal of the anti-cancer drug methotrexate from water by advanced oxidation processes: Aerobic biodegradation and toxicity studies after treatment.

    PubMed

    Lutterbeck, Carlos Alexandre; Baginska, Ewelina; Machado, Ênio Leandro; Kümmerer, Klaus

    2015-12-01

    Anti-cancer drugs are discussed as high risk substances in regard to human health and considered as problematic for the environment. They are of potential environmental relevance due to their poor biodegradability and toxicological properties. Methotrexate (MTX) is an antimetabolite that was introduced in the pharmaceutical market in the 40's and still today is one of the most consumed cytotoxic compounds around the world. In the present study MTX was only partially biodegraded in the closed bottle test (CBT). Therefore, it was submitted to three different advanced oxidation processes (AOPs): UV/H2O2, UV/Fe(2+)/H2O2 and UV/TiO2. The irradiation was carried out with a Hg medium-pressure lamp during 256min whereas the analytical monitoring was done through LC-UV-MS/MS and DOC analysis. MTX was easily removed in all the irradiation experiments, while the highest mineralization values and rates were achieved by the UV/Fe(2+)/H2O2 treatment. The lowest resulted from the UV/H2O2 reactions. The UV/H2O2 treatment resulted in little biodegradable transformation products (TPs). However, the same treatment resulted in a reduction of the toxicity of MTX by forming less toxic TPs. Analysis by LC-UV-MS/MS revealed the existence of nine TPs formed during the photo-catalytic treatments. The pH of the solutions decreased from 6.4 (t 0min) to 5.15 in the UV/H2O2 and from 6.4 (t 0min) to 5.9 in the UV/TiO2 at the end of the experiments. The initial pH of the UV/Fe(2+)/H2O2 experiments was adjusted to 5 and after the addition of H2O2 the pH decreased to around 3 and remained in this range until the end of the treatments. PMID:26298026

  3. MTBE RESEARCH (TREATMENT AND DESTRUCTION BRANCH - LRPCD, NRMRL)

    EPA Science Inventory

    The use of the oxygenate MTBE in gasoline represents one of the largest single use chemicals in the U.S. MTBE can be up to 15 to 25% of the volume of gasoline at the pump. The compound enters the environment through a variety of means. In most cases, leaking underground storage t...

  4. EFFECT OF BTEX AND ETHANOL ON ANAEROBIC BIOTRANSFORMATION OF MTBE

    EPA Science Inventory

    We have recently demonstrated that natural anaerobic biotransformation of MTBE to TBA can account for the natural attenuation of MTBE in a plume from a gasoline spill at Parsippany, New Jersey. It is well established in the literature that the presence of the BTEX compounds natu...

  5. REMEDIAL COSTS FOR MTBE IN SOIL AND GROUND WATER

    EPA Science Inventory

    The extensive contamination of methyl tertiary butyl ether (MTBE) in ground water has introduced concerns about the increased cost of remediation of MTBE releases compared to sites with BTEX only contamination. In an attempt to evaluate these costs, cost information for 311 sit...

  6. REMEDIAL COSTS FOR MTBE IN SOIL AND GROUND WATER

    EPA Science Inventory

    Widespread contamination of methyl tert-butyl ether (MTBE) in ground water has raised concerns about the increased cost of remediation of MTBE releases compared to BTEX-only sites. To evaluate these costs, cost information for 311 sites was furnished by U.S. EPA Office of Underg...

  7. REMEDIAL COSTS FOR MTBE IN SOIL AND GROUND WATER

    EPA Science Inventory

    The extensive contamination of methyl tertiary butyl ether (MTBE) in ground water has introduced concerns about the increased cost of remediation of MTBE releases compared to sites with BTEX only contamination. In an attempt to evaluate these costs, cost information for 311 site...

  8. Ecological hazards of MTBE exposure: A research agenda

    SciTech Connect

    Carlsen, T.; Hall, L.; Rice, D.

    1997-03-01

    Fuel oxygenates are used in metropolitan areas across the United States in order to reduce the amount of carbon monoxide released into the atmosphere during the winter. The most commonly used fuel oxygenate is Methyl tert-butyl ether (MTBE). Its widespread use has resulted in releases into the environment. To date there has been only minimal effort to investigate ecological impacts caused by exposure to concentrations of MTBE typically found in environmental media. Research into the potential for MTBE to adversely affect ecological receptors is essential. Acquisition of such baselines data is especially critical in light of continuing inputs and potential accumulation of MTBE in environmental media. A research Agenda is included in this report and addresses: Assessing Ecological Impacts, Potential Ecological Impacts of MTBE (aquatic organisms, terrestrial organisms), Potential Ecological Endpoints, and A Summary of Research Needs.

  9. REMEDIATION OF MTBE - CONTAMINATED WATER: STUDIES ON THE DEGRADATION OF MTBE INTERMEDIATES USING THE FENTON'S REAGENT

    EPA Science Inventory

    The recent findings of unusual oncentrations of MTBE in groundwater aquifers and surface waters [1] originated most probably from the leaking of underground storage gasoline tanks [2[ has led to a series of judicial and legislative actions, especially in the state of California w...

  10. Hydrocarbon degrading microbial communities in bench scale aerobic biobarriers for gasoline contaminated groundwater treatment.

    PubMed

    Daghio, Matteo; Tatangelo, Valeria; Franzetti, Andrea; Gandolfi, Isabella; Papacchini, Maddalena; Careghini, Alessandro; Sezenna, Elena; Saponaro, Sabrina; Bestetti, Giuseppina

    2015-07-01

    BTEX compounds (benzene, toluene, ethylbenzene and xylenes) and methyl tert-butyl ether (MTBE) are some of the main constituents of gasoline and can be accidentally released in the environment. In this work the effect of bioaugmentation on the microbial communities in a bench scale aerobic biobarrier for gasoline contaminated water treatment was studied by 16S rRNA gene sequencing. Catabolic genes (tmoA and xylM) were quantified by qPCR, in order to estimate the biodegradation potential, and the abundance of total bacteria was estimated by the quantification of the number of copies of the 16S rRNA gene. Hydrocarbon concentration was monitored over time and no difference in the removal efficiency for the tested conditions was observed, either with or without the microbial inoculum. In the column without the inoculum the most abundant genera were Acidovorax, Bdellovibrio, Hydrogenophaga, Pseudoxanthomonas and Serpens at the beginning of the column, while at the end of the column Thauera became dominant. In the inoculated test the microbial inoculum, composed by Rhodococcus sp. CE461, Rhodococcus sp. CT451 and Methylibium petroleiphilum LMG 22953, was outcompeted. Quantitative PCR results showed an increasing in xylM copy number, indicating that hydrocarbon degrading bacteria were selected during the treatment, although only a low increase of the total biomass was observed. However, the bioaugmentation did not lead to an increase in the degradative potential of the microbial communities. PMID:25747304

  11. Sequential anaerobic-aerobic biodegradation of 2,3,7,8-TCDD contaminated soil in the presence of CMC-coated nZVI and surfactant.

    PubMed

    Binh, Nguyen Duy; Imsapsangworn, Chaiyaporn; Kim Oanh, Nguyen Thi; Parkpian, Preeda; Karstensen, Kare; Giao, Pham Huy; DeLaune, Ronald D

    2016-01-01

    Enriched microorganisms in sediment collected from a dioxin-contaminated site in Vietnam (Bien Hoa airbase) were used for examining the effectiveness in biological treatment of 2,3,7,8-Tetrachlorodibenzo-p-dioxin in soil. Four bio-treatments were investigated using a sequential anaerobic (17 weeks) followed by an aerobic (6 weeks) incubation. The maximum removal efficiency was approximately 60% even at an extremely low pH (approx. 3.6) condition. Surfactant Tween-80 was added to enhance the bioavailability of dioxin in two treatments, but it appeared to biostimulate methanogens rather than dechlorinators. As a result, methane production was the highest while the dioxin removal efficiency was the lowest, as compared with the other bio-treatments. Carboxymethylcellulose (CMC) coated on nanoscale zero valent iron (nZVI) surface used in two treatments could prevent the direct contact between bacterial cell surface and nZVI which prevented cell death and lysis, hence enhancing dioxin removal. The presence of CMC--_nZVI in bio-treatments gradually released H2 required for microbiological processes, but the amount used in the experiments were likely too high to maintain optimum H2 levels for biostimulating dechlorinators rather than methanogens. PMID:26179214

  12. NATURAL BIODEGRADATION OF NTBE ON A SITE ON LONG ISLAND, NY: SYMPOSIUM

    EPA Science Inventory

    NRMRL-ADA-00170 Kolhatkar, R., Wilson*, J.T., and Hinshalwood, G. "Natural Biodegradation of NTBE on a Site on Long Island, NY." In: 6th Intl. In-Situ and On-Site Symposium on Bioremediation of MTBE, Alcohols, and Ethers, Battelle, The Si...

  13. Exceptionally Long MTBE Plumes of the Past Have Greatly Diminished.

    PubMed

    McDade, James M; Connor, John A; Paquette, Shawn M; Small, Julia M

    2015-01-01

    Studies published in the late 1990s and early 2000s identified the presence of exceptionally long methyl tert-butyl ether (MTBE) plumes (more than 600 m or 2000 feet) in groundwater and have been cited in technical literature as characteristic of MTBE plumes. However, the scientific literature is incomplete in regard to the subsequent behavior and fate of these MTBE plumes over the past decade. To address this gap, this issue paper compiles recent groundwater monitoring records for nine exceptional plumes that were identified in prior studies. These nine sites exhibited maximum historical MTBE groundwater plume lengths ranging from 820 m (2700 feet) to 3200 m (10,500 feet) in length, exceeding the lengths of 99% of MTBE plumes, as characterized in multiple surveys at underground storage tank sites across the United States. Groundwater monitoring data compiled in our review demonstrate that these MTBE plumes have decreased in length over the past decade, with five of the nine plumes exhibiting decreases of 75% or more compared to their historical maximum lengths. MTBE concentrations within these plumes have decreased by 93% to 100%, with two of the nine sites showing significant decreases (98% and 99%) such that the regulatory authority has subsequently designated the site as requiring no further action. PMID:25691094

  14. Influence of MTBE addition into gasoline on automotive exhaust emissions

    NASA Astrophysics Data System (ADS)

    Poulopoulos, S.; Philippopoulos, C.

    The effect of methyl-t-butyl ether (MTBE) addition into gasoline on the exhaust emissions from internal combustion engines was studied. A four-cylinder OPEL 1.6 l engine equipped with a hydraulic brake dynamometer was used in all the experiments. Fuels containing 0.0-11.0% MTBE were used in a wide range of engine operations, and the exhaust gases were analyzed for CO, HC (total unburned hydrocarbons, methane, ethylene) and MTBE, before and after their catalytic treatment by a three-way catalytic converter. The addition of MTBE into gasoline resulted in a decrease in CO and HC emissions only at high engine loading. During cold-start up of the engine, MTBE, HC, CO emissions were significant and increased with MTBE addition into fuel. At the catalytic converter outlet MTBE was detected when its concentration in fuels was greater than 8% and only as long as the catalytic converter operates at low temperatures. Methane and ethylene emissions were comparable for all fuels tested at engine outlet, but methane emissions remained almost at the same level while ethylene emissions were significantly decreased by the catalytic converter.

  15. Health studies indicate MTBE is safe gasoline additive

    SciTech Connect

    Anderson, E.V.

    1993-09-01

    Implementation of the oxygenated fuels program by EPA in 39 metropolitan areas, including Fairbanks and Anchorage, Alaska, in the winter of 1992, encountered some unexpected difficulties. Complaints of headaches, dizziness, nausea, and irritated eyes started in Fairbanks, jumped to Anchorage, and popped up in various locations in the lower 48 states. The suspected culprit behind these complaints was the main additive for oxygenation of gasoline is methyl tert-butyl ether (MTBE). A test program, hastily organized in response to these complaints, has indicated that MTBE is a safe gasoline additive. However, official certification of the safety of MTBE is still awaited.

  16. Carbon and Hydrogen Isotopic Fractionation during Anaerobic Biodegradation of Benzene

    PubMed Central

    Mancini, Silvia A.; Ulrich, Ania C.; Lacrampe-Couloume, Georges; Sleep, Brent; Edwards, Elizabeth A.; Sherwood Lollar, Barbara

    2003-01-01

    Compound-specific isotope analysis has the potential to distinguish physical from biological attenuation processes in the subsurface. In this study, carbon and hydrogen isotopic fractionation effects during biodegradation of benzene under anaerobic conditions with different terminal-electron-accepting processes are reported for the first time. Different enrichment factors (ɛ) for carbon (range of −1.9 to −3.6‰) and hydrogen (range of −29 to −79‰) fractionation were observed during biodegradation of benzene under nitrate-reducing, sulfate-reducing, and methanogenic conditions. These differences are not related to differences in initial biomass or in rates of biodegradation. Carbon isotopic enrichment factors for anaerobic benzene biodegradation in this study are comparable to those previously published for aerobic benzene biodegradation. In contrast, hydrogen enrichment factors determined for anaerobic benzene biodegradation are significantly larger than those previously published for benzene biodegradation under aerobic conditions. A fundamental difference in the previously proposed initial step of aerobic versus proposed anaerobic biodegradation pathways may account for these differences in hydrogen isotopic fractionation. Potentially, C-H bond breakage in the initial step of the anaerobic benzene biodegradation pathway may account for the large fractionation observed compared to that in aerobic benzene biodegradation. Despite some differences in reported enrichment factors between cultures with different terminal-electron-accepting processes, carbon and hydrogen isotope analysis has the potential to provide direct evidence of anaerobic biodegradation of benzene in the field. PMID:12513995

  17. Evaluating the primary and ready biodegradability of dianilinodithiophosphoric acid.

    PubMed

    Lin, Weixiong; Sun, Shuiyu; Xu, Pingting; Dai, Yongkang; Ren, Jie

    2016-04-01

    Dianilinodithiophosphoric acid (DDA) is widely used as sulfide mineral flotation collector in China. It is necessary to investigate the biodegradability of DDA to provide the fundamental knowledge to assess the environmental fate in the risk assessment of DDA and to design and operate the DDA flotation wastewater biological treatment plant. In the present study, the primary and ready aerobic biodegradations of DDA were studied and the primary biodegradation kinetic model of DDA was developed. The results show that DDA displays a good primary biodegradability and its biodegradation ratio reaches 99.8 % in 7 days. In contrast, DDA is not easily ready biodegradable; hence, it is a partially biodegradable organic compound. The primary aerobic biodegradation kinetics can be described using the first-order reaction kinetics equation: C = 19.72191e(-0.01513t). PMID:27000317

  18. An ex situ evaluation of TBA- and MTBE-baited bio-traps

    PubMed Central

    North, Katharine P.; Mackay, Douglas M.; Annable, Michael D.; Sublette, Kerry L.; Davis, Greg; Holland, Reef B.; Petersen, Daniel; Scow, Kate M.

    2013-01-01

    Aquifer microbial communities can be investigated using Bio-traps® (“bio-traps”), passive samplers containing Bio-Sep® beads (“bio-beads”) that are deployed in monitoring wells to be colonized by bacteria delivered via groundwater flow through the well. When bio-beads are “baited” with organic contaminants enriched in 13C, stable isotope probing allows assessment of the composition and activity of the microbial community. This study used an ex situ system fed by groundwater continuously extracted from an adjacent monitoring well within an experimentally-created aerobic zone treating a tert-butyl alcohol (TBA) plume. The goal was to evaluate aspects of bio-trap performance that cannot be studied quantitatively in situ. The measured groundwater flow through a bio-trap housing suggests that such traps might typically “sample” about 1.8 L per month. The desorption of TBA or methyl tert-butyl ether (MTBE) bait from bio-traps during a typical deployment duration of 6 weeks was approximately 90% and 45%, respectively, of the total initial bait load, with initially high rate of mass loss that decreased markedly after a few days. The concentration of TBA in groundwater flowing by the TBA-baited bio-beads was estimated to be as high as 3400 mg/L during the first few days, which would be expected to inhibit growth of TBA-degrading microbes. Initial inhibition was also implied for the MTBE-baited bio-trap, but at lower concentrations and for a shorter time. After a few days, concentrations in groundwater flowing through the bio-traps dropped below inhibitory concentrations but remained 4–5 orders of magnitude higher than TBA or MTBE concentrations within the aquifer at the experimental site. Desorption from the bio-beads during ex situ deployment occurred at first as predicted by prior sorption analyses of bio-beads but with apparent hysteresis thereafter, possibly due to mass transfer limitations caused by colonizing microbes. These results suggest that

  19. Preparations for Meeting New York and Connecticut MTBE Bans

    EIA Publications

    2003-01-01

    In response to a Congressional request, the Energy Information Administration examined the progress being made to meet the bans on the use of methyl tertiary butyl ether (MTBE) being implemented in New York and Connecticut at the end of 2003.

  20. Iran plans huge private sector MTBE plant

    SciTech Connect

    Alperowicz, N.

    1992-01-15

    An export-oriented 1-million m.t./year methyl tert-butyl ether (MTBE) plant is planned as one of Iran`s private sector investment projects. State-owned National Petrochemical Co (NPC; Tehran) and the Dubai-based Iranian businessman Abdul Wahab Galadari have signed a letter of intent allowing Galadari to develop the venture. Colt Engineering (Calgary, AL) is assisting Galadari with costs, planning and technology selection for the estimated $300-million plus venture. An important meeting with NPC is scheduled end of this month, says Galadari, and a financial package should be put together by end of March or April. The facility will most likely be wholly-owned by the Galadari family, roughly 50% by members resident in Iran and the remainder by the Dubai-based concern A.W. Galadari Sons. NPC says it may take a token shareholding in the venture.

  1. Anaerobic Biodegradation Of Methyl tert-Butyl Ether Under Iron-Reducing Conditions In Batch And Continuous-Flow Cultures

    EPA Science Inventory

    The feasibility of biodegradation of the fuel oxygenate methyl tert-butyl ether (MTBE) under iron-reducing conditions was explored in batch and continuous-flow systems. A porous pot completely-mixed reactor was seeded with diverse cultures and operated under iron-reducing...

  2. Evaluation of biodegradation-promoting additives for plastics.

    PubMed

    Selke, Susan; Auras, Rafael; Nguyen, Tuan Anh; Castro Aguirre, Edgar; Cheruvathur, Rijosh; Liu, Yan

    2015-03-17

    Biodegradation-promoting additives for polymers are increasingly being used around the world with the claim that they effectively render commercial polymers biodegradable. However, there is a lot of uncertainty about their effectiveness in degrading polymers in different environments. In this study, we evaluated the effect of biodegradation-promoting additives on the biodegradation of polyethylene (PE) and polyethylene terephthalate (PET). Biodegradation was evaluated in compost, anaerobic digestion, and soil burial environments. None of the five different additives tested significantly increased biodegradation in any of these environments. Thus, no evidence was found that these additives promote and/or enhance biodegradation of PE or PET polymers. So, anaerobic and aerobic biodegradation are not recommended as feasible disposal routes for nonbiodegradable plastics containing any of the five tested biodegradation-promoting additives. PMID:25723056

  3. Environmental behavior and fate of methyl tert-butyl ether (MTBE)

    USGS Publications Warehouse

    Squillace, Paul J.; Pankow, James F.; Korte, Nic E.; Zogorski, John S.

    1996-01-01

    When gasoline that has been oxygenated with methyl tert-butyl ether (MTBE) comes in contact with water, large amounts of MTBE can dissolve; at 25 degrees Celsius the water solubility of MTBE is about 5,000 milligrams per liter for a gasoline that is 10 percent MTBE by weight. In contrast, for a nonoxygenated gasoline, the total hydrocarbon solubility in water is typically about 120 milligrams per liter. MTBE sorbs only weakly to soil and aquifer materials; therefore, sorption will not significantly retard MTBE's transport by ground water. In addition, MTBE generally resists degradation in ground water. The half-life of MTBE in the atmosphere can be as short as 3 days in a regional airshed. MTBE in the air tends to partition into atmospheric water, including precipitation. However, washout of gas-phase MTBE by precipitation would not, by itself, greatly alter the gas-phase concentration of the compound in the air. The partitioning of MTBE to precipitation is nevertheless strong enough to allow for up to 3 micrograms per liter or more inputs of MTBE to surface and ground water.

  4. MONITORING TO ASSOCIATE A PLUME OF MTBE IN GROUNDWATER WITH A VAPOR RELEASE

    EPA Science Inventory

    There is a class of MTBE plumes in ground water that have little of the BTEX compounds. It has been proposed that these MTBE plumes are caused by release of gasoline vapors from underground storage tanks. However, a mechanism to carry MTBE vapors into ground water has not been ...

  5. INFLUENCE OF METHYL TERT-BUTYL ETHER (MTBE) ON LAKE WATER ALGAE

    EPA Science Inventory

    Methyl tert-butyl ether (MTBE) has been used as an octane booster in gasoline in the United States since the 1970s. MTBE use increased greatly in the 1990s with the implementation of the Clean Air Act Amendments of 1990. The MTBE enhanced a more complete combustion of fuel hydroc...

  6. PERFORMANCE OF MTBE CLEAN-UP TECHNOLOGIES IN NEW YORK STATE

    EPA Science Inventory

    The efficiency of cleanup technologies, based on MTBE concentration reduction, was evaluated for 1,012 UST sites from the State of New York. MTBE concentration reduction was calculated by dividing the maximum BTBE concentration by the current MTBE concentrations and the resul...

  7. Substrate interactions during aerobic biodegradation of benzene

    SciTech Connect

    Arvin, E.; Jensen, B.K.; Gundersen, A.T. )

    1989-12-01

    This study dealt with the interactions with benzene degradation of the following aromatic compounds in a mixed substrate: toluene, o-xylene, naphthalene, 1,4-dimethylnaphthalene, phenanthrene, and pyrrole. The experiment was performed as a factorial experiment with simple batch cultures. The effect of two different types of inocula was tested. One type of inoculum was grown on a mixture of aromatic hydrocarbons; the other was grown on a mixture of aromatic hydrocarbons and nitrogen-, sulfur-, and oxygen-containing aromatic compounds (NSO compounds), similar to some of the compounds identified in creosote waste. The culture grown on the aromatic hydrocarbons and NSO compounds was much less efficient in degrading benzene than the culture grown on only aromatic hydrocarbons. The experiments indicated that toluene- and o-xylene-degrading bacteria are also able to degrade benzene, whereas naphthalene-, 1,,4-dimethylnaphthalene-, and phenanthrene-degrading bacteria have no or very little benzene-degrading ability. Surprisingly, the stimulating effect of toluene and o-xylene was true only if the two compounds were present alone. In combination an antagonistic effect was observed, i.e., the combined effect was smaller than the sum from each of the compounds. The reason for this behavior has not been identified. Pyrrole strongly inhibited benzene degradation even at concentrations of about 100 to 200 micrograms/liter. Future studies will investigate the generality of these findings.

  8. INFLUENCE OF PROTOZOAN GRAZING ON CONTAMINANT BIODEGRADATION. (R825418)

    EPA Science Inventory

    The influence of protozoan grazing on biodegradation rates in samples from contaminated aquifer sediment was evaluated under aerobic and anaerobic conditions. Predator¯prey biomass ratios suggested that protozoan grazing might be influencing bacterial populations....

  9. [Biodegradation characteristics of organic pollutants contained in tannery wastewater].

    PubMed

    Wang, Yong; Li, Wei-Guang; Yang, Li; Su, Cheng-Yuan

    2013-02-01

    In the batch experiments inoculated with activated sludge from tannery wastewater treatment plant, biodegradation characteristics and kinetics of three tanning agents, naphthalene-2-sulfonic sodium, tannic acid and bayberry tannin, were studied under aerobic and anaerobic conditions. And the aerobic/anaerobic biodegradation laws of real tannery wastewater with respect to COD change were also investigated using the same batch experiments. The results showed aerobic degradation was superior to anaerobic degradation for tanning agent removal and mineralization. The removal rates of naphthalene-2-sulfonic sodium, tannic acid and bayberry tannin by aerobic biodegradation were >90% , >90% and 50% -75% , respectively whereas 10%-40%, >95% and 20% -30%, respectively by anaerobic degradation. In terms of COD removal about tannic acid biodegradation, the removal rates under aerobic and anaerobic conditions were >75% and < 75% ,respectively. The first-order kinetic constants during aerobic biodegradation of tannic acid and bayberry tannin were slightly influenced by initial concentrations while initial concentration had a significant effect on the first-order kinetics rate in the case of naphthalene-2-sulfonic sodium aerobic-biodegradation because naphthalene- 2-sulfonic sodium with initial concentration >or= 70 mg.L-1 was toxic to microorganism leading to a significant decline of kinetic constants. Biodegradation of real tannery wastewater under aerobic and anaerobic conditions represented obvious stage characteristics and the COD concentration had a good linear correlation with reaction time in the phases of fast degradation and slow degradation. The aerobic maximum specific degradation rate wqas 11.6 times higher of anaerobic degradation. PMID:23668129

  10. The current status of the U.S. MTBE industry

    SciTech Connect

    Rose, G.M.

    1995-12-31

    This paper reviews the status of the MTBE industry from its beginnings as a result of the Clean Air Act Amendments and the need for the use of oxygenates in non-attainment areas. During 1990--93 three world scale merchant plants were constructed and in 1994 two more were brought on stream. The paper tabulates reasons why MTBE gained the lion`s share of the oxygenates market. Finally the paper discusses the problems that now plague the industry and their causes.

  11. Uptake, metabolism, and toxicity of methyl tert-butyl ether (MTBE) in weeping willows.

    PubMed

    Yu, Xiao-Zhang; Gu, Ji-Dong

    2006-10-11

    Methyl tert-butyl ether (MTBE) is a high volume production chemical and the most commonly used gasoline oxygenate. Uptake, metabolism and toxicity of MTBE in trees were investigated in this study. Pre-rooted weeping willows (Salix babylonica L.) were exposed to hydroponic solution spiked with MTBE and incubated at 25.0+/-1 degrees C for 168 h. The normalized relative transpiration (NRT) rate of weeping willows was used to determine toxicity. MTBE and possible intermediate tert-butyl alcohol (TBA) in solution, tissues of aerial parts of plants, and air were analyzed. Results from the toxicity test showed that severe signs of toxicity (the reduction of the NRT >or=35%) were only found at the treatment group with high doses of MTBE 400 mg L(-1). Neither chlorosis of leaves nor large reduction in the NRT was observed at MTBE exposure to weeping willows MTBE was removed from the hydroponic solution by plants in all treatment groups. Small amounts of MTBE were detected in the plant tissues, but a large fraction of the applied MTBE was found in the air through plant transpiration. Mass balance studies showed that MTBE was assimilated into the plants from hydroponic solution but was not metabolized during transport in the plant. Phytovolatilization was the only relevant removal process for MTBE. Transpiration stream concentration factor (TSCF), an important parameter for design of engineered MTBE phytoremediation systems, was estimated to be 1.12. In conclusion, although this compound is persistent to the attack by plant enzymes, atmospheric MTBE is much more susceptible to photo-oxidation for decomposition. Phytoremediation of MTBE polluted soils and groundwater is an alternative to presently available remediation technologies. PMID:16723185

  12. DEVELOPMENT OF BIOPLUME 4 MODEL FOR FUELS AND CHLORINATED SOLVENT BIODEGRADATION

    EPA Science Inventory

    The Bioplume model has been in development and use for modeling biodegradation and natural attenuation since the late 1980s. Bioplume 1 focused on aerobic biodegradation of BTEX. Bioplume II simulated oxygen and hydrocarbons and simulated biodegradation using an instantaneous r...

  13. DEVELOPMENT OF BIOPLUME4 MODEL FOR FUELS AND CHLORINATED SOLVENT BIODEGRADATION

    EPA Science Inventory

    The Bioplume model has been in development and use for modeling biodegradation and natural attenuation since the late 80's. Bioplume I focused on aerobic biodegradation of BTEX. Bioplume II simulated oxygen and hydrocarbons and simulated biodegradation using an instantaneous re...

  14. TREATMENT OF MTBE-CONTAMINATED WATERS WITH FENTON'S REAGENT

    EPA Science Inventory

    Methyl tertiary-butyl ether (MTBE) has been commonly used as a fuel additive because of its many favorable properties that allow it to improve fuel combustion and reduce resulting concentrations of carbon monoxide and unburnt hydrocarbons. Unfortuantely, increased production a...

  15. HEALTH RISK ISSUES RELATED TO MTBE IN DRINKING WATER

    EPA Science Inventory

    Despite the attention given to methyl tertiary butyl ether (MTBE) as a contaminant in ground water and surface water, the implications of such contamination for human health have not been clearly established to date. Limitations in the databases for both exposure and health effe...

  16. DETERMINING HOW VAPOR PHASE MTBE REACHES GROUND WATER

    EPA Science Inventory

    EPA Region 2 and ORD have funded a RARE project for FY 2005/2006 to evaluate the prospects that MTBE (and other fuel components) in vapors that escape from an underground storage tank (UST) can find its way to ground water produced by monitoring wells at a gasoline filling statio...

  17. LOCALIZED RECHARGE INFLUENCES ON MTBE TRANSPORT AND WELL PLACEMENT CONSIDERATIONS

    EPA Science Inventory

    Vertical characterization of a gasoline release site at East Patchogue, New York showed that methyl tert-butyl ether (MTBE) and aromatic plumes "dived" as they passed beneath a sand pit. That this behavior was caused by aquifer recharge was shown by two pieces of evidence. Fir...

  18. MTBE: THE CURRENT STATUS OF HEALTH AND ENVIRONMENTAL ISSUES

    EPA Science Inventory

    This presentation will provide an update on recent evaluations of the environmental and health issues surrounding the use of MTBE in gasoline in the United States and elsewhere. Several public health bodies around the world have recently evaluated aspects of the health risks of ...

  19. MTBE BIOREMEDIATION WITH BIONETS CONTAINING ISOLITE, PMI, SOS ON AIR

    EPA Science Inventory

    Methyl tert-Butyl Ether (MTBE), a gasoline additive, is a persistent and foul tasting contaminant that is more mobile in ground water than BTEX. It is turning up at many American crossroads. This study's objective was to determine if biologically active in situ Bionets could bior...

  20. Kinetics of the oxidation of methyl tert-butyl ether (MTBE) by potassium permanganate.

    PubMed

    Damm, Jochen H; Hardacre, Christopher; Kalin, Robert M; Walsh, Kayleen P

    2002-08-01

    The occurrence of the fuel oxygenate methyl tert-butyl ether (MTBE) in the environment has received considerable scientific attention. The pollutant is frequently found in the groundwater due to leaking of underground storage tanks or pipelines. Concentrations of more than several mg/L MTBE were detected in groundwater at several places in the US and Germany in the last few years. In situ chemical oxidation is a promising treatment method for MTBE-contaminated plumes. This research investigated the reaction kinetics for the oxidation of MTBE by permanganate. Batch tests demonstrated that the oxidation of MTBE by permanganate is second order overall and first order individually with respect to permanganate and MTBE. The second-order rate constant was 1.426 x 10(-6) L/mg/h. The influence of pH on the reaction rate was demonstrated to have no significant effect. However, the rate of MTBE oxidation by potassium permanganate is 2-3 orders of magnitude lower than of other advanced oxidation processes. The slower rates of MTBE oxidation by permanganate limit the applicability of this process for rapid MTBE cleanup strategies. However, permanganate oxidation of MTBE has potential for passive oxidation risk management strategies. PMID:12230210

  1. Current trends in trichloroethylene biodegradation: a review.

    PubMed

    Shukla, Awadhesh Kumar; Upadhyay, Siddh Nath; Dubey, Suresh Kumar

    2014-06-01

    Over the past few years biodegradation of trichloroethylene (TCE) using different microorganisms has been investigated by several researchers. In this review article, an attempt has been made to present a critical summary of the recent results related to two major processes--reductive dechlorination and aerobic co-metabolism used for TCE biodegradation. It has been shown that mainly Clostridium sp. DC-1, KYT-1, Dehalobacter, Dehalococcoides, Desulfuromonas, Desulfitobacterium, Propionibacterium sp. HK-1, and Sulfurospirillum bacterial communities are responsible for the reductive dechlorination of TCE. Efficacy of bacterial communities like Nitrosomonas, Pseudomonas, Rhodococcus, and Xanthobacter sp. etc. for TCE biodegradation under aerobic conditions has also been examined. Mixed cultures of diazotrophs and methanotrophs have been used for TCE degradation in batch and continuous cultures (biofilter) under aerobic conditions. In addition, some fungi (Trametes versicolor, Phanerochaete chrysosporium ME-446) and Actinomycetes have also been used for aerobic biodegradation of TCE. The available information on kinetics of biofiltration of TCE and its degradation end-products such as CO2 are discussed along with the available results on the diversity of bacterial community obtained using molecular biological approaches. It has emerged that there is a need to use metabolic engineering and molecular biological tools more intensively to improve the robustness of TCE degrading microbial species and assess their diversity. PMID:23057686

  2. MTBE and gasoline hydrocarbons in ground water of the United States.

    PubMed

    Moran, Michael J; Zogorski, John S; Squillace, Paul J

    2005-01-01

    The occurrence of methyl tert-butyl ether (MTBE) and gasoline hydrocarbons was examined in three types of studies of ground water conducted by the U.S. Geological Survey: major aquifer surveys, urban land-use studies, and agricultural land-use studies. The detection frequency of MTBE was dependent on the study type, with the highest detection frequency in urban land-use studies. Only 13 ground water samples from all study types, or 0.3%, had concentrations of MTBE that exceeded the lower limit of the U.S. EPA's Drinking-Water Advisory. The detection frequency of MTBE was highest in monitoring wells located in urban areas and in public supply wells. The detection frequency of any gasoline hydrocarbon also was dependent on study type and generally was less than the detection frequency of MTBE. The probability of detecting MTBE in ground water was strongly associated with population density, use of MTBE in gasoline, and recharge. Ground water in areas with high population density, in areas where MTBE is used as a gasoline oxygenate, and in areas with high recharge rates had a greater probability of MTBE occurrence. Also, ground water from public supply wells and shallow ground water underlying urban land-use areas had a greater probability of MTBE occurrence compared to ground water from domestic wells and ground water underlying rural land-use areas. The probability of detecting MTBE in ground water was weakly associated with the density of leaking underground storage tanks, soil permeability, and aquifer consolidation, and only concentrations of MTBE >0.5 microg/L were associated with dissolved oxygen. PMID:16029187

  3. Marine Oil Biodegradation.

    PubMed

    Hazen, Terry C; Prince, Roger C; Mahmoudi, Nagissa

    2016-03-01

    Crude oil has been part of the marine environment for millions of years, and microbes that use its rich source of energy and carbon are found in seawater, sediments, and shorelines from the tropics to the polar regions. Catastrophic oil spills stimulate these organisms to "bloom" in a reproducible fashion, and although oil does not provide bioavailable nitrogen, phosphorus or iron, there are enough of these nutrients in the sea that when dispersed oil droplets dilute to low concentrations these low levels are adequate for microbial growth. Most of the hydrocarbons in dispersed oil are degraded in aerobic marine waters with a half-life of days to months. In contrast, oil that reaches shorelines is likely to be too concentrated, have lower levels of nutrients, and have a far longer residence time in the environment. Oil that becomes entrained in anaerobic sediments is also likely to have a long residence time, although it too will eventually be biodegraded. Thus, data that encompass everything from the ecosystem to the molecular level are needed for understanding the complicated process of petroleum biodegradation in marine environments. PMID:26698270

  4. [Fluorescence fingerprint transformation of municipal wastewater caused by aerobic treatment].

    PubMed

    Wu, Jing; Cui, Shuo; Xie, Chao-bo; Cao, Zhi-ping; Chen, Mao-fu; Lü, Yan-li

    2011-12-01

    The conventional parameters such as COD and BOD only could represent information about total organic content. Fluorescence spectrum can display organic composition and it is unique for each sample, so it is referred as "fluorescence fingerprint". In the present study transformation of excitation-emission matrix of municipal wastewater with sewage as major components after aerobic treatment was investigated and then the zones of biodegradable and non-biodegradable organic matters were figured out: the fluorescence at excitation wavelength/emission wavelength of about 280/340 nm and 225/240 nm derived from biodegradable organics and those of the zone of excitation wavelength above 300 nm and the zone of excitation wavelength below 300 nm and emission wavelength above 400 nm were mainly related with non-biodegradable organics. The above-mentioned results indicated that fluorescence fingerprint could be used to evaluate the performance and instruct design and operation of aerobic systems. PMID:22295782

  5. Summary report on the aerobic degradation of diesel fuel and the degradation of toluene under aerobic, denitrifying and sulfate reducing conditions

    SciTech Connect

    Coyne, P.; Smith, G.

    1995-08-15

    This report contains a number of studies that were performed to better understand the technology of the biodegradation of petroleum hydrocarbons. Topics of investigation include the following: diesel fuel degradation by Rhodococcus erythropolis; BTEX degradation by soil isolates; aerobic degradation of diesel fuel-respirometry; aerobic degradation of diesel fuel-shake culture; aerobic toluene degradation by A3; effect of HEPES, B1, and myo-inositol addition on the growth of A3; aerobic and anaerobic toluene degradation by contaminated soils; denitrifying bacteria MPNs; sulfate-reducing bacteria MPNs; and aerobic, DNB and SRB enrichments.

  6. The effect of fuel alcohol on monoaromatic hydrocarbon biodegradation and natural attenuation.

    PubMed

    Alvarez, Pedro J J; Hunt, Craig S

    2002-01-01

    The proposed replacement of the gasoline oxygenate MTBE with ethanol represents potential economic and environmental quality benefits. However, these benefits may be offset to some extent by potential detrimental effects on groundwater quality and natural attenuation of released petroleum products. The objectives of this literature review are to bound the extent to which these impacts may occur, summarize the available information on the biodegradation of ethanol in the environment, assess the potential effect that biodegradation processes may have on the fate and transport of BTEX compounds, and provide recommendations for research to enhance related risk assessment and management decisions. Ethanol that reaches groundwater aquifers is likely to be degraded at much faster rates than other gasoline constituents. If the carbon source is not limiting, a preferential degradation of ethanol over BTEX may be observed under both aerobic and anaerobic conditions. Depending on the extent of the release, ethanol may exert a high biochemical oxygen demand that would contribute to the rapid depletion of dissolved oxygen in the groundwater. Thus, ethanol will likely be degraded predominantly under anaerobic conditions. None of the potential ethanol metabolites that could accumulate in groundwater are toxic, although some potential biodegradation by-products such as butyrate could adversely affect the taste and odor of drinking water sources. In addition, acetate and other volatile fatty acids could accumulate at high concentrations, causing a pH decrease in poorly buffered systems. It is unknown, however, whether the pH would decrease to a point that inhibits natural degradative processes. Inhibition of microbial, activity near the source is likely to occur as a result of exposure to high alcohol concentrations, and bactericidal effects are likely to occur when cells are exposed to ethanol concentrations exceeding 10,000 mg/L. However, the maximum allowable ethanol content in

  7. THE PHOTOCATALYTIC OXIDATION OF LOW CONCENTRATION MTBE ON TITANIUM DIOXIDE FROM GROUNDWATER IN A FALLING FILM REACTOR

    EPA Science Inventory

    This study focuses on three objectives: 1) to determine the feasibility of using a falling-film slurry photocatalytic reactor for the degradation of MTBE in water, 2) to assess the feasibility of MTBE photo-oxidation on TiO2 at low initial MTBE concentrations (<10 mg/L), and 3) t...

  8. MTBE OXIDATION BYPRODUCTS FROM THE TREATMENT OF SURFACE WATERS BY OZONATION AND UV-OZONATION

    EPA Science Inventory

    In recent years, there has been considerable concern over the release of methyl tert-butyl ether (MTBE), as gasoline additive, into the aquifers used as potable water sources. MTBE readily dissolves in water and has entered the environment via gasoline spills and leaking...

  9. Iron Amendment and Fenton Oxidation of MTBE-Spent Granular Activated Carbon

    EPA Science Inventory

    Fenton-driven regeneration of Methyl tert-butyl ether (MTBE)-spent granular activated carbon (GAC) involves Fe amendment to the GAC to catalyze H2O2 reactions and to enhance the rate of MTBE oxidation and GAC regeneration. Four forms of iron (ferric sulfate, ferric chloride, fer...

  10. Fenton-like Degradation of MTBE: Effects of Iron Counter Anion and Radical Scavengers

    EPA Science Inventory

    Fenton-driven oxidation of Methyl tert-butyl ether (MTBE) (0.11-0.16 mM) in batch reactors containing ferric iron (5 mM), hydrogen peroxide (H2O2) (6 mM) (pH=3) was performed to investigate MTBE transformation mechanisms. Independent variables included the form of iron (Fe) (Fe2(...

  11. Used motor oil as a source of MTBE, TAME, and BTEX to ground water

    USGS Publications Warehouse

    Baker, R.J.; Best, E.W.; Baehr, A.L.

    2002-01-01

    Methyl tert-butyl ether (MTBE), the widely used gasoline oxygenate, has been identified as a common ground water contaminant, and BTEX compounds (benzene, toluene, ethylbenzene, and xylenes) have long been associated with gasoline spills. Because not all instances of ground water contamination by MTBE and BTEX can be attributed to spills or leaking storage tanks, other potential sources need to be considered. In this study, used motor oil was investigated as a potential source of these contaminants. MTBE in oil was measured directly by methanol extraction and gas chromatography using a flame ionization detector (GC/FID). Water was equilibrated with oil samples and analyzed for MTBE, BTEX, and the oxygenate tert-amyl methyl ether (TAME) by purge-and-trap concentration followed by GC/FID analysis. Raoult's law was used to calculate oil-phase concentrations of MTBE, BTEX, and TAME from aqueous-phase concentrations. MTBE, TAME, and BTEX were not detected in any of five new motor oil samples, whereas these compounds were found at significant concentrations in all six samples of the used motor oil tested for MTBE and all four samples tested for TAME and BTEX. MTBE concentrations in used motor oil were on the order of 100 mg/L. TAME concentrations ranged from 2.2 to 87 mg/L. Concentrations of benzene were 29 to 66 mg/L, but those of other BTEX compounds were higher, typically 500 to 2000 mg/L.

  12. Determination of MTBE in a recreational harbor using solid-phase microextraction.

    PubMed

    Zuccarello, Joseph L; Ganske, Jane A; Green, David B

    2003-06-01

    Discovery of the fuel additive methyl tert-butyl ether (MTBE) in groundwater, surface water, and stormwater has prompted studies of its sources, transport and fate. More limited data, however, is available on the extent of contamination of coastal waters, as well as the persistence of MTBE in the marine environment. We apply here the combination of solid phase microextraction and gas chromatography-mass spectrometry to the detection of sub-to-low microgram/l concentrations of MTBE in seawater samples. Analysis of samples collected at the Marina del Rey harbor, a shallow recreational harbor near Los Angeles, CA, show MTBE contamination in the low microgram/l level. MTBE measurements were made at different depths, from the surface to the bottom, at five sites within the harbor during months showing no measurable precipitation. The highest concentration of MTBE (18 microgram/l) was found at the boat launching ramp, and the lowest (0.2 microgram/l) near the harbor entrance, approximately 2.3 km from the ramp. The levels of MTBE measured, as well as their variation over the study period, are fully consistent with recreational boating as the primary source of contamination. No evidence for MTBE contamination from the adjacent stormwater control channel was noted. PMID:12668039

  13. MICROBIAL ANALYSIS OF MTBE, BTEX BIOREMEDIATION: BIONETS CONTAINING PM1, SOS, ISOLITE.

    EPA Science Inventory

    MTBE and BTEX (benzene, toluene, ethylbenzene, and xylene) are major problems of many sites in the United States. The objective of this study was to determine if biologically active in-situ BioNets could bioremediation MTBE and BTEX contaminated groundwater. Seven BioNets were ...

  14. MICROBIAL ANALYSIS OF MTBE, BTEX BIOREMEDIATION: BIONETS(TM) CONTAINING PM1, SOS, ISOLITE (R)

    EPA Science Inventory

    MTBE and BTEX (benzene, toluene, ethylbenzene, and xylene) are major problems of many sites in the United States. The objective of this study was to determine if biologically active in-situ BioNets could bioremediation MTBE and BTEX contaminated groundwater. Seven BioNets were ...

  15. BTEX AND MTBE BIOREMEDIATION: BIONETS™ CONTAINING SOS, PM1 AND ISOLITE®

    EPA Science Inventory

    MTBE and BTEX (benzene, toluene, ethylbenzene, and xylenes) are major problems of many sites in the United States. The objective of this study was to determine if biologically active in situ BioNets could bioremediate MTBE and BTEX contaminated groundwater. Seven BioNets w...

  16. Impact of Renewable Fuels Standard/MTBE Provisions of S. 1766

    EIA Publications

    2002-01-01

    This service report addresses the Renewable Fuels Standard (RFS)/methyl tertiary butyl ether (MTBE) provisions of S. 1766. The 'S. 1766' Case reflects provisions of S. 1766 including a renewable fuels standard (RFS) reaching five billion gallons by 2012, a complete phase-out of MTBE within four years, and the option for states to waive the oxygen requirement for reformulated gasoline (RFG).

  17. Fenton-Driven Chemical Regeneration of MTBE-Spent Granular Activated Carbon -- A Pilot Study

    EPA Science Inventory

    MTBE-spent granular activated carbon (GAC) underwent 3 adsorption/oxidation cycles. Pilot-scale columns were intermittently placed on-line at a ground water pump and treat facility, saturated with MTBE, and regenerated with H2O2 under different chemical, physical, and operational...

  18. MICROBIAL ANALYSIS OF MTBE, BTEX BIOREMEDIATION: BIONETS CONTAINING PM1, SOS, ISOLITE�

    EPA Science Inventory

    MTBE and BTEX (benzene, toluene, ethylbenzene, and xylene) are major problems of many sites in the United States. The objective of this study was to determine if biologically active in-situ BioNets could bioremediate MTBE and BTEX contaminated groundwater. Seven BioNets were plac...

  19. CHEMICAL DESTRUCTION OF MTBE USING FENTON'S REAGENT: EFFECT OF FERROUS IRON/HYDROGEN PEROXIDE RATIO

    EPA Science Inventory

    In previous laboratory experiments Fenton's Reagent (FR) was successfully used as the source of hydroxyl radicals (OH*) for chemical treatment of low concentrations of methyl tert-butyl ether (MTBE) in water. Although under certain conditions MTBE degradation levels as high as 99...

  20. OCCURRENCE OF METYL TERT-BUTYL ETHER (MTBE) AT FIVE MARINAS IN LAKE TEXOMA

    EPA Science Inventory



    Occurrence of methyl tert-butyl ether (MTBE) in five marinas was monitored between June 1999 and November 2000 in Lake Texoma located on the border of Oklahoma and Texas. MTBE is a commonly used gasoline additive and a suspected carcinogen. Lake water was collected at loc...

  1. Field Treatment of MTBE-Contaiminated Groundwater Using Ozone/UV Oxidation

    EPA Science Inventory

    Methyl-tertiary butyl ether (MTBE) is often found in groundwater as a result of gasoline spills and leaking underground storage tanks. An extrapolation of occurrence data in 2008 estimated at least one detection of MTBE in approximately 165 small and large public water systems se...

  2. INHALATION EXPOSURE TO METHYL TERT-BUTYL ETHER (MTBE) AND DIBROMOCHLOROMETHANE (DBCM) USING CONTINUOUS BREATH ANALYSIS

    EPA Science Inventory

    The oxygenate methyl tert-butyl ether (MTBE) has been added to gasoline to help meet national ambient air quality standards in those parts of the U.S. that are non-compliant for carbon monoxide. Although MTBE has provided important health benefits in terms of reduced haza...

  3. CONTROLLED, SHORT-TERM DERMAL AND INHALATION EXPOSURE TO MTBE AND DIBROMOCHLOROMETHANE

    EPA Science Inventory

    The oxygenate methyl tert-butyl ether (MTBE) has been added to gasoline to meet national ambient air quality standards in those parts of the US that are non-compliant for carbon monoxide. Although MTBE has provided important health benefits in terms of reduced hazardous air po...

  4. IMPACT OF ETHANOL ON THE NATURAL ATTENUATION OF MTBE IN A NORMALLY SULFATE-REDUCING AQUIFER

    EPA Science Inventory

    Two side-by-side experiments were conducted in an MTBE-contaminated aquifer at a former service station site to determine the effect of ethanol release on the fate of pre-existing MTBE contamination. On one side, we injected groundwater amended with 1-3 mg/L benzene, toluene, and...

  5. EFFECT OF BTEX ON THE DEGRADATION OF MTBE AND TBA BY MIXED BACTERIAL CONSORTIUM

    EPA Science Inventory

    Methyl tert-butyl ether (MTBE) contamination in groundwater often coexists with benzene, toluene, ethylbenzene, and xylene (BTEX) near the source of the plume. Tertiary butyl alcohol (TBA) is a prevalent intermediate of MTBE degradation. Therefore, there is a significant p...

  6. Persulfate Oxidation of MTBE- and Chloroform-Spent Granular Activated Carbon

    EPA Science Inventory

    Activated persulfate (Na2S2O8) regeneration of methyl tert-butyl ether (MTBE) and chloroform-spent GAC was evaluated in this study. Thermal-activation of persulfate was effective and resulted in greater MTBE removal than either alkaline-activation or H2O2–persulfate binary mixtur...

  7. Evaluation of combustion by-products of MTBE as a component of reformulated gasoline.

    PubMed

    Franklin, P M; Koshland, C P; Lucas, D; Sawyer, R F

    2001-01-01

    Methyl tertiary-butyl ether (MTBE) is a gasoline oxygenate that is widely used throughout the US and Europe as an octane-booster and as a means of reducing automotive carbon monoxide (CO) emissions. The combustion by-products of pure MTBE have been evaluated in previous laboratory studies, but little attention has been paid to the combustion by-products of MTBE as a component of gasoline. MTBE is often used in reformulated gasoline (RFG), which has chemical and physical characteristics distinct from conventional gasoline. The formation of MTBE by-products in RFG is not well-understood, especially under "worst-case" vehicle emission scenarios such as fuel-rich operations, cold-starts or malfunctioning emission control systems, conditions which have not been studied extensively. Engine-out automotive dynamometer studies have compared RFG with MTBE to non-oxygenated RFG. Their findings suggest that adding MTBE to reformulated gasoline does not impact the high temperature flame chemistry in cylinder combustion processes. Comparison of tailpipe and exhaust emission studies indicate that reactions in the catalytic converter are quite effective in destroying most hydrocarbon MTBE by-product species. Since important reaction by-products are formed in the post-flame region, understanding changes in this region will contribute to the understanding of fuel-related changes in emissions. PMID:11219713

  8. Lab-scale experimental strategy for determining micropollutant partition coefficient and biodegradation constants in activated sludge.

    PubMed

    Pomiès, M; Choubert, J M; Wisniewski, C; Miège, C; Budzinski, H; Coquery, M

    2015-03-01

    The nitrifying/denitrifying activated sludge process removes several micropollutants from wastewater by sorption onto sludge and/or biodegradation. The objective of this paper is to propose and evaluate a lab-scale experimental strategy for the determination of partition coefficient and biodegradation constant for micropollutant with an objective of modelling their removal. Four pharmaceutical compounds (ibuprofen, atenolol, diclofenac and fluoxetine) covering a wide hydrophobicity range (log Kow from 0.16 to 4.51) were chosen. Dissolved and particulate concentrations were monitored for 4 days, inside two reactors working under aerobic and anoxic conditions, and under different substrate feed conditions (biodegradable carbon and nitrogen). We determined the mechanisms responsible for the removal of the target compounds: (i) ibuprofen was biodegraded, mainly under aerobic conditions by cometabolism with biodegradable carbon, whereas anoxic conditions suppressed biodegradation; (ii) atenolol was biodegraded under both aerobic and anoxic conditions (with a higher biodegradation rate under aerobic conditions), and cometabolism with biodegradable carbon was the main mechanism; (iii) diclofenac and fluoxetine were removed by sorption only. Finally, the abilities of our strategy were evaluated by testing the suitability of the parameters for simulating effluent concentrations and removal efficiency at a full-scale plant. PMID:25300180

  9. Biodegradable Polydepsipeptides

    PubMed Central

    Feng, Yakai; Guo, Jintang

    2009-01-01

    This paper reviews the synthesis, characterization, biodegradation and usage of bioresorbable polymers based on polydepsipeptides. The ring-opening polymerization of morpholine-2,5-dione derivatives using organic Sn and enzyme lipase is discussed. The dependence of the macroscopic properties of the block copolymers on their structure is also presented. Bioresorbable polymers based on polydepsipeptides could be used as biomaterials in drug controlled release, tissue engineering scaffolding and shape-memory materials. PMID:19333423

  10. Application of first order kinetics to characterize MTBE natural attenuation in groundwater.

    PubMed

    Metcalf, Meredith J; Stevens, Graham J; Robbins, Gary A

    2016-04-01

    Methyl tertiary butyl ether (MTBE) was a gasoline oxygenate that became widely used in reformulated gasoline as a means to reduce air pollution in the 1990s. Unfortunately, many of the underground storage tanks containing reformulated gasoline experienced subsurface releases which soon became a health concern given the increase in public and private water supplies containing MTBE. Many states responded to this by banning the use of MTBE as an additive, including Connecticut. Although MTBE dissipates by natural attenuation, it continues to be prevalent in groundwater long after the Connecticut ban in 2004. This study estimated the rate of the natural attenuation in groundwater following the Connecticut ban by evaluating the MTBE concentration two years prior to and two years after the MTBE ban at eighty-three monitoring wells from twenty-two retail gasoline stations where MTBE contamination was observed. Sites chosen for this study had not undergone active remediation ensuring no artificial influence to the natural attenuation processes that controls the migration and dissipation of MTBE. Results indicate that MTBE has dissipated in the natural environment, at more than 80% of the sites and at approximately 82% of the individual monitoring wells. In general, dissipation approximated first order kinetics. Dissipation half-lives, calculated using concentration data from the two year period after the ban, ranged from approximately three weeks to just over seven years with an average half-life of 7.3 months with little variability in estimates for different site characteristics. The accuracy of first order estimates to predict further MTBE dissipation were tested by comparing predicted concentrations with those observed after the two year post-ban period; the predicted concentrations closely match the observed concentrations which supports the use of first order kinetics for predictions of this nature. PMID:26878650

  11. Application of first order kinetics to characterize MTBE natural attenuation in groundwater

    NASA Astrophysics Data System (ADS)

    Metcalf, Meredith J.; Stevens, Graham J.; Robbins, Gary A.

    2016-04-01

    Methyl tertiary butyl ether (MTBE) was a gasoline oxygenate that became widely used in reformulated gasoline as a means to reduce air pollution in the 1990s. Unfortunately, many of the underground storage tanks containing reformulated gasoline experienced subsurface releases which soon became a health concern given the increase in public and private water supplies containing MTBE. Many states responded to this by banning the use of MTBE as an additive, including Connecticut. Although MTBE dissipates by natural attenuation, it continues to be prevalent in groundwater long after the Connecticut ban in 2004. This study estimated the rate of the natural attenuation in groundwater following the Connecticut ban by evaluating the MTBE concentration two years prior to and two years after the MTBE ban at eighty-three monitoring wells from twenty-two retail gasoline stations where MTBE contamination was observed. Sites chosen for this study had not undergone active remediation ensuring no artificial influence to the natural attenuation processes that controls the migration and dissipation of MTBE. Results indicate that MTBE has dissipated in the natural environment, at more than 80% of the sites and at approximately 82% of the individual monitoring wells. In general, dissipation approximated first order kinetics. Dissipation half-lives, calculated using concentration data from the two year period after the ban, ranged from approximately three weeks to just over seven years with an average half-life of 7.3 months with little variability in estimates for different site characteristics. The accuracy of first order estimates to predict further MTBE dissipation were tested by comparing predicted concentrations with those observed after the two year post-ban period; the predicted concentrations closely match the observed concentrations which supports the use of first order kinetics for predictions of this nature.

  12. Microbial toxicity of methyl tert-butyl ether (MTBE) determined with fluorescent and luminescent bioassays.

    PubMed

    Roslev, Peter; Lentz, Trine; Hesselsoe, Martin

    2015-02-01

    The inhibitory effects of the fuel additive methyl tert-butyl ether (MTBE) and potential degradation products tert-butanol (TBA) and formaldehyde was examined using mixed microbial biomass, and six strains of bioluminescent bacteria and yeast. The purpose was to assess microbial toxicity with quantitative bioluminescent and fluorescent endpoints, and to identify sensitive proxies suitable for monitoring MTBE contamination. Bioluminescent Aliivibrio fischeri DSM 7151 (formerly Vibrio fischeri) appeared highly sensitive to MTBE exposure, and was a superior test organisms compared to lux-tagged Escherichia coli DH5α, Pseudomonas fluorescens DF57-40E7 and Saccharomyces cerevisiae BLYR. EC10 and EC50 for acute MTBE toxicity in A. fischeri were 1.1 and 10.9 mg L(-1), respectively. Long term (24h) MTBE exposure resulted in EC10 values of 0.01 mg L(-1). TBA was significantly less toxic with EC10 and EC50 for acute and chronic toxicity >1000 mg L(-1). Inhibition of bioluminescence was generally a more sensitive endpoint for MTBE toxicity than measuring intracellular ATP levels and heterotrophic CO2 assimilation. A weak estrogenic response was detected for MTBE at concentrations ⩾ 3.7 g L(-1) using an estrogen inducible bioluminescent yeast strain (S. cerevisiae BLYES). Microbial hydrolytic enzyme activity in groundwater was affected by MTBE with EC10 values of 0.5-787 mg L(-1), and EC50 values of 59-3073 for alkaline phosphatase, arylsulfatase, beta-1,4-glucanase, N-acetyl-beta-d-glucosaminidase, and leucine-aminopeptidase. Microbial alkaline phosphatase and beta-1,4-glucanase activity were most sensitive to MTBE exposure with EC50 ⩽ 64.8 mg L(-1). The study suggests that bioassays with luminescent A. fischeri, and fluorescent assays targeting hydrolytic enzyme activity are good candidates for monitoring microbial MTBE toxicity in contaminated water. PMID:25128634

  13. Contamination of Groundwater in California by MTBE: How Do We Constrain the Problem?

    NASA Astrophysics Data System (ADS)

    Nugal, K. A.; Tong, W.; McNulty, B. A.

    2006-12-01

    The purpose of this project is to characterize and assess the contamination of groundwater in California by methyl tertiary-butyl ether (MTBE). Field data were collected by reviewing 85 leaking underground storage tank cases in Orange County, California in the Santa Ana Regional Quality Control Board Region 8. Our analytical study shows that the concentration of MTBE ranged from a minimum of 370 ppb to a maximum of 1,200,000 ppb contamination levels. The state of California considers levels >5 ppb of MTBE to be a concern. In order to estimate the length of the MTBE plumes, MTBE concentrations from the source well and one or more down-gradient monitoring wells were integrated into an Excel program based on the Domenico analytical model (1987). After the calibrations were estimated by adjusting values in longitudinal dispersivity, groundwater velocity and degradation rate constant, the horizontal MTBE plume length (maximum distance between source well and plume edge with a MCL <5pbb) was predicted. The data collected produced plume lengths ranging from 69 feet to 2790 feet. The mean calculated plume length was 760 feet. The future objective of the project is to present a comparative analysis of MTBE groundwater contamination between different hydrogeologic settings (e.g., fractured-controlled vs. alluvial-controlled) by reviewing underground storage tank cases in several regions across the state (e.g., California State Water Resources Control Regional Boards 1 (North Coast), 2 (San Francisco Bay), 5 (Central Valley), 6 (Lahontan), 8 (Santa Ana), and 9 (San Diego). The results from this project will (1) further characterize the nature of MTBE plumes, (2) provide data that can be used in future investigation, remediation and monitoring of MTBE plume sites, and (3) lead to refinement of groundwater transport models for MTBE plumes.

  14. BIODEGRADATION OF SEDIMENT-BOUND PAHS IN FIELD-CONTAMINATED SEDIMENT

    EPA Science Inventory

    The biodegradation of polycyclic aromatic hydrocarbons (PAHs) has been reported to occur under aerobic, sulfate reducing, and denitrifying conditions. PAHs present in contaminated sites, however, are known for their persistence. Most published studies were conducted in systems wh...

  15. Methyl tert-butyl ether in ground and surface water of the United States: National-scale relations between MTBE occurrence in surface and ground water and MTBE use in gasoline

    USGS Publications Warehouse

    Moran, M.J.; Clawges, R.M.; Zogorski, J.S.

    2002-01-01

    The detection frequency of methyl tert-butyl ether (MTBE) in ground and surface water of the United States is positively related to the content of MTBE in gasoline in various metropolitan areas of the U.S. The frequency of detection of MTBE is generally higher in areas that use larger amounts of MTBE in gasoline. Sampling of surface and ground water by the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program between 1993 and 1998 revealed a frequent detection of low concentrations of MTBE. In this analysis, data from several national-scale gasoline surveys are examined and data from one survey that is most extensive in geographic and temporal coverage is used to relate the detection of MTBE in ground and surface water to the volumetric content of MTBE in gasoline.

  16. A numerical investigation of oxygen concentration dependence on biodegradation rate laws in vapor intrusion

    PubMed Central

    Yao, Yijun; Shen, Rui; Pennel, Kelly G.; Suuberg, Eric M.

    2013-01-01

    In subsurface vapor intrusion, aerobic biodegradation has been considered as a major environmental factor that determines the soil gas concentration attenuation factors for contaminants such as petroleum hydrocarbons. The site investigation showed that oxygen could play an important role in this biodegradation rate, and this paper explores the influence of oxygen concentration in biodegradation reactions included in vapor intrusion (VI) models. Two different three dimensional (3-D) numerical models of vapor intrusion were explored for their sensitivity to the form of the biodegradation rate law. A second order biodegradation rate law, explicitly including oxygen concentration dependence, was introduced into one model. The results indicate that the aerobic/anoxic interface depth is determined by the ratio of contaminant source vapor to atmospheric oxygen concentration, and that the contaminant concentration profile in the aerobic zone was significantly influenced by the choice of rate law. PMID:24197079

  17. A numerical investigation of oxygen concentration dependence on biodegradation rate laws in vapor intrusion.

    PubMed

    Yao, Yijun; Shen, Rui; Pennel, Kelly G; Suuberg, Eric M

    2013-12-01

    In subsurface vapor intrusion, aerobic biodegradation has been considered as a major environmental factor that determines the soil gas concentration attenuation factors for contaminants such as petroleum hydrocarbons. The site investigation has shown that oxygen can play an important role in this biodegradation rate, and this paper explores the influence of oxygen concentration on biodegradation reactions included in vapor intrusion (VI) models. Two different three dimensional (3-D) numerical models of vapor intrusion were explored for their sensitivity to the form of the biodegradation rate law. A second order biodegradation rate law, explicitly including oxygen concentration dependence, was introduced into one model. The results indicate that the aerobic/anoxic interface depth is determined by the ratio of contaminant source vapor to atmospheric oxygen concentration, and that the contaminant concentration profile in the aerobic zone was significantly influenced by the choice of rate law. PMID:24197079

  18. Linking Low-Level Stable Isotope Fractionation to Expression of the Cytochrome P450 Monooxygenase-Encoding ethB Gene for Elucidation of Methyl tert-Butyl Ether Biodegradation in Aerated Treatment Pond Systems▿ †

    PubMed Central

    Jechalke, Sven; Rosell, Mònica; Martínez-Lavanchy, Paula M.; Pérez-Leiva, Paola; Rohwerder, Thore; Vogt, Carsten; Richnow, Hans H.

    2011-01-01

    Multidimensional compound-specific stable isotope analysis (CSIA) was applied in combination with RNA-based molecular tools to characterize methyl tertiary (tert-) butyl ether (MTBE) degradation mechanisms occurring in biofilms in an aerated treatment pond used for remediation of MTBE-contaminated groundwater. The main pathway for MTBE oxidation was elucidated by linking the low-level stable isotope fractionation (mean carbon isotopic enrichment factor [ɛC] of −0.37‰ ± 0.05‰ and no significant hydrogen isotopic enrichment factor [ɛH]) observed in microcosm experiments to expression of the ethB gene encoding a cytochrome P450 monooxygenase able to catalyze the oxidation of MTBE in biofilm samples both from the microcosms and directly from the ponds. 16S rRNA-specific primers revealed the presence of a sequence 100% identical to that of Methylibium petroleiphilum PM1, a well-characterized MTBE degrader. However, neither expression of the mdpA genes encoding the alkane hydroxylase-like enzyme responsible for MTBE oxidation in this strain nor the related MTBE isotope fractionation pattern produced by PM1 could be detected, suggesting that this enzyme was not active in this system. Additionally, observed low inverse fractionation of carbon (ɛC of +0.11‰ ± 0.03‰) and low fractionation of hydrogen (ɛH of −5‰ ± 1‰) in laboratory experiments simulating MTBE stripping from an open surface water body suggest that the application of CSIA in field investigations to detect biodegradation may lead to false-negative results when volatilization effects coincide with the activity of low-fractionating enzymes. As shown in this study, complementary examination of expression of specific catabolic genes can be used as additional direct evidence for microbial degradation activity and may overcome this problem. PMID:21148686

  19. The fate of MtBE during Fenton-like treatments through laboratory scale column tests

    NASA Astrophysics Data System (ADS)

    Piscitelli, Daniela; Zingaretti, Daniela; Verginelli, Iason; Gavasci, Renato; Baciocchi, Renato

    2015-12-01

    In Situ Chemical Oxidation (ISCO) based on the Fenton's process is a proven technology for the treatment of groundwater contaminated by organic compounds. Nevertheless, the application of this treatment process to methyl tert-butyl ether (MtBE) is questioned, as there are concerns about its capacity to achieve complete mineralization. Many existing studies have focused on water contaminated by MtBE and are thus not representative of in situ treatments since they do not consider the presence of soil. In this work, the effectiveness of a Fenton-like process for MtBE treatment was proven in soil column tests performed at operating conditions (i.e., oxidant and contaminant concentration and flow rates) resembling those typically used for in situ applications. No MtBE by-products were detected in any of the tested conditions, thus suggesting that the tert-butyl group of MtBE was completely degraded. A mass balance based on the CO2 produced was used as evidence that most of the MtBE removed was actually mineralized. Finally, the obtained results show that preconditioning of soil with a chelating agent (EDTA) significantly enhanced MtBE oxidation.

  20. Hydraulic performance of a proposed in situ photocatalytic reactor for degradation of MTBE in water.

    PubMed

    Lim, Leonard Lik Pueh; Lynch, Rod

    2011-01-01

    Methyl tert-butyl ether (MTBE) groundwater remediation projects often require a combination of technologies resulting in increasing the project costs. A cost-effective in situ photocatalytic reactor design, Honeycomb II, is proposed and tested for its efficiency in MTBE degradation at various flows. This study is an intermediate phase of the research in developing an in situ photocatalytic reactor for groundwater remediation. It examines the effect of the operating variables: air and water flow and double passages through Honeycomb II, on the MTBE removal. MTBE vaporisation is affected by not only temperature, Henry's law constant and air flow to volume ratio but also reactor geometry. The column reactor achieved more than 84% MTBE removal after 8 h at flows equivalent to horizontal groundwater velocities slower than 21.2 cm d⁻¹. Despite the contrasting properties between a photocatalytic indicator methylene blue and MTBE, the reactor efficiency in degrading both compounds showed similar responses towards flow (equivalent groundwater velocity and hydraulic residence time (HRT)). The critical HRT for both compounds was approximately 1 d, which corresponded to a velocity of 21.2 cm d⁻¹. A double pass through both new and used catalysts achieved more than 95% MTBE removal after two passes in 48 h. It also verified that the removal efficiency can be estimated via the sequential order of the removal efficiency of one pass obtained in the laboratory. This study reinforces the potential of this reactor design for in situ groundwater remediation. PMID:21067793

  1. The fate of MtBE during Fenton-like treatments through laboratory scale column tests.

    PubMed

    Piscitelli, Daniela; Zingaretti, Daniela; Verginelli, Iason; Gavasci, Renato; Baciocchi, Renato

    2015-12-01

    In Situ Chemical Oxidation (ISCO) based on the Fenton's process is a proven technology for the treatment of groundwater contaminated by organic compounds. Nevertheless, the application of this treatment process to methyl tert-butyl ether (MtBE) is questioned, as there are concerns about its capacity to achieve complete mineralization. Many existing studies have focused on water contaminated by MtBE and are thus not representative of in situ treatments since they do not consider the presence of soil. In this work, the effectiveness of a Fenton-like process for MtBE treatment was proven in soil column tests performed at operating conditions (i.e., oxidant and contaminant concentration and flow rates) resembling those typically used for in situ applications. No MtBE by-products were detected in any of the tested conditions, thus suggesting that the tert-butyl group of MtBE was completely degraded. A mass balance based on the CO2 produced was used as evidence that most of the MtBE removed was actually mineralized. Finally, the obtained results show that preconditioning of soil with a chelating agent (EDTA) significantly enhanced MtBE oxidation. PMID:26544517

  2. [Occupational exposure to methyl tert-butyl ether (MTBE) at an oil refinery].

    PubMed

    Perbellini, L; Pasini, F; Prigioni, P; Rosina, A

    2003-01-01

    Methyl tert-butyl ether (MTBE) is widely used as an additive to gasoline, to increase oxygen content and reduce tailpipe emission of carbon monoxide. Our research dealt with 37 refinery workers in order to measure their occupational exposure to MTBE during two different seasonal periods. They provided blood and urine samples before and after a work shift during which they wore an active charcoal sampler for solvents. All samples were analysed by a gas-chromatograph equipped with a mass spectrometer detector. The concentration in air of MTBE was very low (median: 25 micrograms/m3 in spring and 5 micrograms/m3 in autumn). The blood and urine concentrations of MTBE at the end of the work shift were higher than those found before the shift. The increment in biological samples confirmed a small intake of MTBE by refinery workers: the biological monitoring of occupational exposure to this solvent yielded reliable results. Blood and urinary concentrations of MTBE obtained from workers split in relation to their smoking habit did not give a statistic significance to say that cigarette smoke is not a confusion factor in monitoring exposure to MTBE. PMID:14979074

  3. Effect of H2 and redox condition on biotic and abiotic MTBE transformation

    USGS Publications Warehouse

    Bradley, P.M.; Chapelle, F.H.; Landmeyer, J.E.

    2006-01-01

    Laboratory studies conducted with surface water sediment from a methyl tert-butyl ether (MTBE)-contaminated site in South Carolina demonstrated that, under methanogenic conditions, [U-14C] MTBE was transformed to 14C tert-butyl alcohol (TBA) with no measurable production of 14CO2. Production of TBA was not attributed to the activity of methanogenic microorganisms, however, because comparable transformation of [U-14C] MTBE to 14C-TBA also was observed in heat-sterilized controls with dissolved H2 concentrations > 5 nM. The results suggest that the transformation of MTBE to TBA may be an abiotic process that is driven by biologically produced H2 under in situ conditions. In contrast, mineralization of [U-14C] MTBE to 14CO2 was completely inhibited by heat sterilization and only observed in treatments characterized by dissolved H2 concentrations < 2 nM. These results suggest that the pathway of MTBE transformation is influenced by in situ H2 concentrations and that in situ H2 concentrations may be an useful indicator of MTBE transformation pathways in ground water systems.

  4. Hypothesis-driven weight of evidence analysis to determine potential endocrine activity of MTBE.

    PubMed

    de Peyster, Ann; Mihaich, Ellen

    2014-08-01

    Endocrine-related endpoints in animals have been reported to respond to high doses of methyl tertiary-butyl ether (MTBE), however, a systematic and transparent evaluation of endocrine potential has not been published. Resolving whether MTBE exhibits endocrine activity is important given regulatory and public interest in endocrine disrupting substances and their potential for causing adverse effects in humans or wildlife. A weight-of-evidence (WoE) analysis was conducted, focusing on hypotheses related to the potential for MTBE to interact with estrogen, androgen, and thyroid pathways, and steroidogenesis. To reach scientifically justified conclusions based on the totality of evidence, this WoE procedure involved a semi-quantitative relevance weighting of each endpoint for each hypothesis and systematic consideration of each endpoint in various study designs. This procedure maximized use of an extensive body of relevant and reliable literature on MTBE with evidence supporting or opposing a given mode of action hypothesis. Evaluating the strength and consistency of observations from many MTBE studies also provided a way to assess whether high doses used in experiments with MTBE confound identification of direct endocrine system responses. Based on results of studies using mammalian and fish models and in vitro screening assays, this WoE assessment reveals that MTBE lacks direct endocrine activity. PMID:24813373

  5. Biodegradation of biodiesel fuels

    SciTech Connect

    Zhang, X.; Haws, R.; Wright, B.; Reese, D.; Moeller, G.; Peterson, C.

    1995-12-31

    Biodiesel fuel test substances Rape Ethyl Ester (REE), Rape Methyl Ester (RME), Neat Rape Oil (NR), Say Methyl Ester (SME), Soy Ethyl Ester (SEE), Neat Soy Oil (NS), and proportionate combinations of RME/diesel and REE/diesel were studied to test the biodegradability of the test substances in an aerobic aquatic environment using the EPA 560/6-82-003 Shake Flask Test Method. A concurrent analysis of Phillips D-2 Reference Diesel was also performed for comparison with a conventional fuel. The highest rates of percent CO{sub 2} evolution were seen in the esterified fuels, although no significant difference was noted between them. Ranges of percent CO{sub 2} evolution for esterified fuels were from 77% to 91%. The neat rape and neat soy oils exhibited 70% to 78% CO{sub 2} evolution. These rates were all significantly higher than those of the Phillips D-2 reference fuel which evolved from 7% to 26% of the organic carbon to CO{sub 2}. The test substances were examined for BOD{sub 5} and COD values as a relative measure of biodegradability. Water Accommodated Fraction (WAF) was experimentally derived and BOD{sub 5} and COD analyses were carried out with a diluted concentration at or below the WAF. The results of analysis at WAF were then converted to pure substance values. The pure substance BOD{sub 5} and COD values for test substances were then compared to a control substance, Phillips D-2 Reference fuel. No significant difference was noted for COD values between test substances and the control fuel. (p > 0.20). The D-2 control substance was significantly lower than all test substances for BCD, values at p << 0.01. RME was also significantly lower than REE (p < 0.05) and MS (p < 0.01) for BOD{sub 5} value.

  6. Removal of MTBE from a clay soil using electrokinetic technique.

    PubMed

    Estabragh, A R; Bordbar, A T; Ghaziani, F; Javadi, A A

    2016-01-01

    Remediation of a soil contaminated with methyl tertiary butyl ether (MTBE) was studied by using the electrokinetic technique. A series of experimental tests were carried out on contaminated soil in an electro-osmotic apparatus at different applied gradients of voltage and time. The tests were conducted with distilled water and ethylenediaminetetra acetic acid (EDTA) solution as electrolyte. During each test the values of pH at anode and cathode reservoirs and also the discharge from cathode were measured. At the end of each test a number of soil samples were extracted from the middle of the soil at different distances from the anode and the removal of contaminant was measured by a gas chromatography apparatus. The results indicate that with EDTA as electrolyte the highest efficiency for removal of MTBE is achieved with 2.0 V/cm gradient and in the duration of 14 days. In addition, EDTA causes the values of pH to increase and decrease in the cathode and anode reservoirs, respectively. It also decreases the effluent and electro-osmotic permeability in comparison with distilled water. Experimental data were analysed by ANOVA and t-test methods. These statistical analyses showed significant difference (at 5% level) between the reference and other tests. PMID:26787321

  7. National survey of MTBE and other VOCs in community drinking-water sources

    USGS Publications Warehouse

    Clawges, Rick M.; Rowe, Barbara L.; Zogorski, John S.

    2001-01-01

    Methyl tert-butyl ether (MTBE) is a volatile organic compound (VOC) that is added to gasoline either seasonally or year round in many parts of the United States to increase the octane level and to reduce carbon monoxide and ozone levels in the air. The chemical properties and widespread use of MTBE can result in contamination of private and public drinking-water sources. MTBE contamination is a concern in drinking water because of the compound's low taste and odor threshold and potential human-health effects.

  8. Quantifying RDX biodegradation in groundwater using δ15N isotope analysis

    NASA Astrophysics Data System (ADS)

    Bernstein, Anat; Adar, Eilon; Ronen, Zeev; Lowag, Harald; Stichler, Willibald; Meckenstock, Rainer U.

    2010-01-01

    Isotope analysis was used to examine the extent of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) biodegradation in groundwater along a ca. 1.35-km contamination plume. Biodegradation was proposed as a natural attenuating remediation method for the contaminated aquifer. By isotope analysis of RDX, the extent of biodegradation was found to reach up to 99.5% of the initial mass at a distance of 1.15-1.35 km down gradient from the contamination sources. A range of first-order biodegradation rates was calculated based on the degradation extents, with average half-life values ranging between 4.4 and 12.8 years for RDX biodegradation in the upper 15 m of the aquifer, assuming purely aerobic biodegradation, and between 10.9 and 31.2 years, assuming purely anaerobic biodegradation. Based on the geochemical data, an aerobic biodegradation pathway was suggested as the dominant attenuation process at the site. The calculated biodegradation rate was correlated with depth, showing decreasing degradation rates in deeper groundwater layers. Exceptionally low first-order kinetic constants were found in a borehole penetrating the bottom of the aquifer, with half life ranging between 85.0 to 161.5 years, assuming purely aerobic biodegradation, and between 207.5 and 394.3 years, assuming purely anaerobic biodegradation. The study showed that stable isotope fractionation analysis is a suitable tool to detect biodegradation of RDX in the environment. Our findings clearly indicated that RDX is naturally biodegraded in the contaminated aquifer. To the best of our knowledge, this is the first reported use of RDX isotope analysis to quantify its biodegradation in contaminated aquifers.

  9. MONITORING POLYCHLORINATED BIPHENYLS (PCBS) BIODEGRADATION USING CONTINUOUS-FLOW ISOTOPE RATIO MASS SPECTROMETRY

    EPA Science Inventory

    Research has shown that polychlorinated biphenyls (PCBs) in some cases can be removed from the environment by biodegradation. Aerobic and anaerobic biological processes have been determined in previous research to be capable of degrading PCBs. During the aerobic and anaerobic d...

  10. COMPOUND-SPECIFIC STABLE ISOTOPE ANALYSIS TO DEMONSTRATE IN-SITU MTBE BIOTRANSFORMATION

    EPA Science Inventory

    Change of stable isotope composition of organic contaminants (isotopic fractionation) is a useful indicator of biotransformation. Most of applications to date are in the area of chlorinated solvents and recently BTEX, MTBE and TBA. Chemical reactions (biotic- and abiotic transfor...

  11. Isolation and characterization of a new Mycobacterium austroafricanum strain, IFP 2015, growing on MTBE.

    PubMed

    Lopes Ferreira, Nicolas; Maciel, Helena; Mathis, Hugues; Monot, Frédéric; Fayolle-Guichard, Françoise; Greer, Charles W

    2006-04-01

    A new Mycobacterium austroafricanum strain, IFP 2015, growing on methyl tert-butyl ether (MTBE) as a sole carbon source was isolated from an MTBE-degrading microcosm inoculated with drain water of an MTBE-supplemented gasoline storage tank. M. austroafricanum IFP 2015 was able to grow on tert-butyl formate, tert-butyl alcohol (TBA) and alpha-hydroxyisobutyrate. 2-Methyl-1,2-propanediol was identified as the TBA oxidation product in M. austroafricanum IFP 2015 and in the previously isolated M. austroafricanum IFP 2012. M. austroafricanum IFP 2015 also degraded ethyl tert-butyl ether more rapidly than M. austroafricanum IFP 2012. Specific primers designed to monitor the presence of M. austroafricanum strains could be used as molecular tools to detect similar strains in MTBE-contaminated environment. PMID:16028043

  12. INFLUENCE OF METHYL TERT-BUTYL ETHER (MTBE) ON LAKE WATER ALGAE: JOURNAL ARTICLE

    EPA Science Inventory

    NRMRL-ADA-01209 Kampbell*, D.H., An, Y, and Williams, VR. Influence of Methyl tert-Butyl Ether (MTBE) on Lake Water Algae. Bulletin of Environmental Contamination and Toxicology 57 (4):675-681 (2001). ...

  13. Teaching Aerobic Fitness Concepts.

    ERIC Educational Resources Information Center

    Sander, Allan N.; Ratliffe, Tom

    2002-01-01

    Discusses how to teach aerobic fitness concepts to elementary students. Some of the K-2 activities include location, size, and purpose of the heart and lungs; the exercise pulse; respiration rate; and activities to measure aerobic endurance. Some of the 3-6 activities include: definition of aerobic endurance; heart disease risk factors;…

  14. Automobile proximity and indoor residential concentrations of BTEX and MTBE

    SciTech Connect

    Corsi, Dr. Richard; Morandi, Dr. Maria; Siegel, Dr. Jeffrey; Hun, Diana E

    2011-01-01

    Attached garages have been identified as important sources of indoor residential air pollution. However, the literature lacks information on how the proximity of cars to the living area affects indoor concentrations of gasoline-related compounds, and the origin of these pollutants. We analyzed data from the Relationships of Indoor, Outdoor, and Personal Air (RIOPA) study and evaluated 114 residences with cars in an attached garage, detached garage or carport, or without cars. Results indicate that homes with cars in attached garages were affected the most. Concentrations in homes with cars in detached garages and residences without cars were similar. The contribution from gasoline-related sources to indoor benzene and MTBE concentrations appeared to be dominated by car exhaust, or a combination of tailpipe and gasoline vapor emissions. Residing in a home with an attached garage could lead to benzene exposures ten times higher than exposures from commuting in heavy traffic.

  15. Route-to-route extrapolation of the toxic potency of MTBE.

    PubMed

    Dourson, M L; Felter, S P

    1997-12-01

    MTBE is a volatile organic compound used as an oxygenating agent in gasoline. Inhalation from fumes while refueling automobiles is the principle route of exposure for humans, and toxicity by this route has been well studied. Oral exposures to MTBE exist as well, primarily due to groundwater contamination from leaking stationary sources, such as underground storage tanks. Assessing the potential public health impacts of oral exposures to MTBE is problematic because drinking water studies do not exist for MTBE, and the few oil-gavage studies from which a risk assessment could be derived are limited. This paper evaluates the suitability of the MTBE database for conducting an inhalation route-to-oral route extrapolation of toxicity. This includes evaluating the similarity of critical effect between these two routes, quantifiable differences in absorption, distribution, metabolism, and excretion, and sufficiency of toxicity data by the inhalation route. We conclude that such an extrapolation is appropriate and have validated the extrapolation by finding comparable toxicity between a subchronic gavage oral bioassay and oral doses we extrapolate from a subchronic inhalation bioassay. Our results are extended to the 2-year inhalation toxicity study by Chun et al. (1992) in which rats were exposed to 0, 400, 3000, or 8000 ppm MTBE for 6 hr/d, 5 d/wk. We have estimated the equivalent oral doses to be 0, 130, 940, or 2700 mg/kg/d. These equivalent doses may be useful in conducting noncancer and cancer risk assessments. PMID:9463928

  16. Comparison of MTBE concentrations in groundwater of urban and nonurban areas in Germany.

    PubMed

    Kolb, Axel; Püttmann, Wilhelm

    2006-11-01

    The occurrence of the gasoline oxygenate methyl tert-butyl ether (MTBE) in groundwater samples from known fuel-contaminated sites (n=29 samples), nonurban (n=74) and urban sites (n=67) in Germany was investigated. The analyses revealed detection frequencies of 58% (contaminated sites), 24% (nonurban sites) and 63% (urban sites) at a detection limit of 0.01 microgL(-1). Median (maximum) MTBE concentrations were calculated for nonurban and urban samples as 0.18 microgL(-1) (2.2 microgL(-1)) and 0.06 microgL(-1) (48 microg L(-1)). The data from nonurban samples revealed MTBE detections mainly at public supply wells with higher pumping rates than monitoring wells. MTBE was more frequently detected in urban samples, most probably due to the higher atmospheric input and direct liquid emissions from motorways or gas stations. Higher concentrations above 1.0 microgL(-1) in urban areas were found in wells located at industrial sites, where also a MTBE plume was accidentally detected during the study. The prevalence of MTBE in shallow aquifers was comparable to those in the USA. PMID:17011019

  17. PCB biodegradation: Laboratory studies transitioned into the field

    SciTech Connect

    Abramowicz, D.A.

    1993-12-31

    Two distinct bacterial systems are known to be involved in PCB biotransformations. Both aerobic PCB biodegradation (Oxidative attack) and anaerobic PCB dechlorination (reductive attack) have been demonstrated in the laboratory. These results have been successfully reproducted in recent experiments performed in aquatic sediments. In 1991, GE performed a large scale test of in situ aerobic PCB biodegradation in the Upper Hudson River. The experiments involved six sealed caissons (six feet in diameter) lowered into Aroclor 1242 contaminated sediments that had already undergone extensive anaerobic PCB dechlorination. Stimulation of indigenous PCB-degrading microorganisms resulted in >50% biodegradation over 10 weeks. A large scale stimulation of in situ anaerobic PCB dechlorination in Housatonic River sediments contaminated with untransformed Aroclor 1260 was initiated in 1992. The experiments similarly involve six sealed caissons (six feet in diameter) lowered into contaminated sediments to investigate new methods developed to accelerate PCB dechlorination in the field. Preliminary results from this ongoing field test will be discussed.

  18. Relations between the detection of methyl tert-butyl ether (MTBE) in surface and ground water and its content in gasoline

    USGS Publications Warehouse

    Moran, M.J.; Halde, M.J.; Clawges, R.M.; Zogorski, J.S.

    2000-01-01

    The relations between the content of MTBE in gasoline and the detection frequency of MTBE in ground and surface water were analyzed using the percent by volume of MTBE in gasoline provided by NIPER. For groundwater, 21 metropolitan areas had information on detection frequency and percent volume of MTBE in gasoline, while for surface water, only 9 metropolitan areas had this information. For groundwater, three cities, i.e., Columbia, SC, Harrisburg, PA, and Norfolk, VA, had values of MTBE in gasoline for only 2 sampling periods and had a MTBE in gasoline for only 2 sampling periods. The frequency of detection of MTBE in surface and ground water had a positive relation to content of MTBE in gasoline. The occurrence of the fuel additive MTBE in ground and surface water was related to its issue in gasoline. The frequency of detection of MTBE was higher in areas that use greater amounts of MTBE in gasoline. As the percent by volume of MTBE in gasoline increased, the frequency of detection of MTBE in ground and surface water increased.

  19. Anaerobic and aerobic transformation of TNT

    SciTech Connect

    Kulpa, C.F.; Boopathy, R.; Manning, J.

    1996-12-31

    Most studies on the microbial metabolism of nitroaromatic compounds have used pure cultures of aerobic microorganisms. In many cases, attempts to degrade nitroaromatics under aerobic conditions by pure cultures result in no mineralization and only superficial modifications of the structure. However, mixed culture systems properly operated result in the transformation of 2,4,6-trinitrotoluene (TNT) and in some cases mineralization of TNT occurs. In this paper, the mixed culture system is described with emphasis on intermediates and the characteristics of the aerobic microbial process including the necessity for a co-substrate. The possibility of removing TNT under aerobic/anoxic conditions is described in detail. Another option for the biodegradation of TNT and nitroaromatics is under anaerobic, sulfate reducing conditions. In this instance, the nitroaromatic compounds undergo a series of reductions with the formation of amino compounds. TNT under sulfate reducing conditions is reduced to triaminotoluene presumably by the enzyme nitrite reductase, which is commonly found in many Desulfovibrio spp. The removal of nitro groups from TNT is achieved by a series of reductive reactions with the formation of ammonia and toluene by Desulfovibrio sp. (B strain). These metabolic processes could be applied to other nitroaromatic compounds like nitrobenzene, nitrobenzoic acids, nitrophenols, and aniline. The data supporting the anaerobic transformation of TNT under different growth condition are reviewed in this report.

  20. Fenton-like degradation of MTBE: Effects of iron counter anion and radical scavengers.

    PubMed

    Hwang, Sangchul; Huling, Scott G; Ko, Saebom

    2010-01-01

    Fenton-driven oxidation of methyl tert-butyl ether (MTBE) (0.11-0.16mM) in batch reactors containing ferric iron (5mM) and hydrogen peroxide (H(2)O(2)) (6mM) (pH=3) was performed to investigate MTBE transformation mechanisms. Independent variables included the forms of iron (Fe) (Fe(2)(SO(4))(3).9H(2)O and Fe(NO(3))(3).9H(2)O), H(2)O(2) (6, 60mM), chloroform (CF) (0.2-2.4mM), isopropyl alcohol (IPA) (25, 50mM), and sulfate (7.5mM). MTBE, tert-butyl alcohol and acetone transformation were significantly greater when oxidation was carried out with Fe(NO(3))(3).9H(2)O than with Fe(2)(SO(4))(3).9H(2)O. Sulfate interfered in the formation of the ferro-peroxy intermediate species, inhibited H(2)O(2) reaction, hydroxyl radical (()OH) formation, and MTBE transformation. Transformation was faster and more complete at a higher [H(2)O(2)] (60mM), but resulted in lower oxidation efficiency which was attributed to ()OH scavenging by H(2)O(2). CF scavenging of the superoxide radical (()O(2)(-)) in the ferric nitrate system resulted in lower rates of ()O(2)(-) reduction of Fe(III) to Fe(II), ()OH production, and consequently lower rates of MTBE transformation. IPA, an excellent scavenger of ()OH, completely inhibited MTBE transformation in the ferric nitrate system indicating oxidation was predominantly by ()OH. ()OH scavenging by HSO(4)(-), formation of the sulfate radical (()SO(4)(-)), and oxidation of MTBE by ()SO(4)(-) was estimated to be negligible. The form of Fe (i.e., counter anion) selected for use in Fenton treatment systems impacts oxidative mechanisms, treatment efficiency, and post-oxidation treatment of residuals which may require additional handling and cost. PMID:19959205

  1. Biodegradable synthetic bone composites

    DOEpatents

    Liu, Gao; Zhao, Dacheng; Saiz, Eduardo; Tomsia, Antoni P.

    2013-01-01

    The invention provides for a biodegradable synthetic bone composition comprising a biodegradable hydrogel polymer scaffold comprising a plurality of hydrolytically unstable linkages, and an inorganic component; such as a biodegradable poly(hydroxyethylmethacrylate)/hydroxyapatite (pHEMA/HA) hydrogel composite possessing mineral content approximately that of human bone.

  2. A water extraction, static headspace sampling, gas chromatographic method to determine MTBE in heating oil and diesel fuel.

    PubMed

    Cummins, T M; Robbins, G A; Henebry, B J; Goad, C R; Gilbert, E J; Miller, M E; Stuart, J D

    2001-03-15

    A method was developed to determine the fuel/water partition coefficient (KMTBE) of methyl tert-butyl ether (MTBE) and then used to determine low parts per million concentrations of MTBE in samples of heating oil and diesel fuel. A special capillary column designed for the separation of MTBE and to prevent coelution and a gas chromatograph equipped with a photoionization detector (PID) were used. MTBE was partitioned from fuel samples into water during an equilibration step. The water samples were then analyzed for MTBE using static headspace sampling followed by GC/PID. A mathematical relationship was derived that allowed a KMTBE value to be calculated by utilizing the fuel/water volume ratios and the corresponding PID signal. KMTBE values were found to range linearly from 3.8 to 10.9 over a temperature range of 5-40 degrees C. This analysis method gave a MDL of 0.7 ppm MTBE in the fuel and a relative average accuracy of +/-15% by comparison with an independent laboratory using purge and trap GC/ MS analysis. MTBE was found in home heating oil in residential tanks and in diesel fuel at service stations throughout the state of Connecticut. The levels of MTBE were found to vary significantly with time. Heating oil and diesel fuel from terminals were also found to contain MTBE. This research suggests thatthe reported widespread contamination of groundwater with MTBE may also be due to heating oil and diesel fuel releases to the environment. used extensively for the past 20 years as a gasoline additive (up to 15 wt %) to reduce automobile carbon monoxide and hydrocarbon emissions. The fact that MTBE is highly soluble in water (approximately 5 wt %) (3) and chemically inert when compared to other fuel constituents causes it to be often detected at high concentrations in groundwater in the vicinity of gasoline spills. The EPA has reported that low levels of MTBE in drinking water (above 40 microg/L) may cause unpleasant taste and odors and has designated MTBE as a

  3. Biodegradation of fat, oil and grease (FOG) deposits under various redox conditions relevant to sewer environment.

    PubMed

    He, Xia; Zhang, Qian; Cooney, Michael J; Yan, Tao

    2015-07-01

    Fat, oil and, grease (FOG) deposits are one primary cause of sanitary sewer overflows (SSOs). While numerous studies have examined the formation of FOG deposits in sewer pipes, little is known about their biodegradation under sewer environments. In this study, FOG deposit biodegradation potential was determined by studying the biodegradation of calcium palmitate in laboratory under aerobic, nitrate-reducing, sulfate-reducing, and methanogenic conditions. Over 110 days of observation, calcium palmitate was biodegraded to CO2 under aerobic and nitrate-reducing conditions. An approximate 13 times higher CO2 production rate was observed under aerobic condition than under nitrate-reducing condition. Under sulfate-reducing condition, calcium palmitate was recalcitrant to biodegradation as evidenced by small reduction in sulfate. No evidence was found to support calcium palmitate degradation under methanogenic condition in the simulated sewer environment. Dominant microbial populations in the aerobic and nitrate-reducing microcosms were identified by Illumina seqeuncing, which may contain the capability to degrade calcium palmitate under both aerobic and nitrate-reducing conditions. Further study on these populations and their functional genes could shed more light on this microbial process and eventually help develop engineering solutions for SSOs control in the future. PMID:25715780

  4. MTBE ambient water quality criteria development: a public/private partnership.

    PubMed

    Mancini, E R; Steen, A; Rausina, G A; Wong, D C L; Arnold, W R; Gostomski, F E; Davies, T; Hockett, J R; Stubblefield, W A; Drottar, K R; Springer, T A; Errico, P

    2002-01-15

    A public/private partnership was established in 1997, under the administrative oversight of the American Petroleum Institute (API), to develop aquatic toxicity data sufficient to calculate ambient water quality criteria for methyl tertiary-butyl ether (MTBE), a gasoline oxygenate. The MTBE Water Quality Criteria Work Group consisted of representatives from private companies, trade associations, and USEPA. Funding was provided by the private entities, while aquatic biological/toxicological expertise was provided by industry and USEPA scientists. This public/private partnership constituted a nonadversarial, cost-effective, and efficient process for generating the toxicity data necessary for deriving freshwater and marine ambient water quality criteria. Existing aquatic toxicity data were evaluated for acceptability, consistent with USEPA guidance, and nineteen freshwater and marine tests were conducted by commercial laboratories as part of this effort to satisfy the federal criteria database requirements. Definitive test data were developed and reported under the oversight of industry study monitors and Good Laboratory Practice standards auditors, and with USEPA scientists participating in advisory and critical review roles. Calculated, preliminary freshwater criteria for acute (Criterion Maximum Concentration) and chronic (Criterion Continuous Concentration) exposure effect protection are 151 and 51 mg MTBE/L, respectively. Calculated, preliminary marine criteria for acute and chronic exposure effect protection are 53 and 18 mg MTBE/L, respectively. These criteria values may be used for surface water quality management purposes, and they indicate that ambient MTBE concentrations documented in U. S. surface waters to date do not constitute a risk to aquatic organisms. PMID:11831214

  5. Trends in the occurrence of MTBE in drinking water in the Northeast United States

    USGS Publications Warehouse

    Moran, M.J.

    2007-01-01

    Public water systems in Connecticut, Maine, Maryland, New Hampshire, New Jersey, and Rhode Island sampled treated drinking water from 1993-2006 and analyzed the samples for MTBE. The US Geological Survey examined trends in the occurrence of MTBE in drinking water derived from ground water in these States for two near-decadal time steps; 1993-1999 and 2000-2006. MTBE was detected in 14% of drinking water samples collected in all States from 1993-1999 and in 19% of drinking water samples collected from the same systems from 2000-2006 and this difference was statistically significant. Trends in the occurrence of MTBE in each State by individual year indicated significant positive trends in Maryland and New Hampshire. Significant, increasing trends in MTBE concentrations were observed in Maryland and Rhode Island by individual year. This is an abstract of a paper presented at the 2007 Petroleum Hydrocarbons and Organic Chemicals in Ground Water: Prevention, Assessment and Remediation Conference (Houston, TX 11/5-6/2007).

  6. Impact of metals on the biodegradation of organic pollutants.

    PubMed Central

    Sandrin, Todd R; Maier, Raina M

    2003-01-01

    Forty percent of hazardous waste sites in the United States are co-contaminated with organic and metal pollutants. Data from both aerobic and anaerobic systems demonstrate that biodegradation of the organic component can be reduced by metal toxicity. Metal bioavailability, determined primarily by medium composition/soil type and pH, governs the extent to which metals affect biodegradation. Failure to consider bioavailability rather than total metal likely accounts for much of the enormous variability among reports of inhibitory concentrations of metals. Metals appear to affect organic biodegradation through impacting both the physiology and ecology of organic degrading microorganisms. Recent approaches to increasing organic biodegradation in the presence of metals involve reduction of metal bioavailability and include the use of metal-resistant bacteria, treatment additives, and clay minerals. The addition of divalent cations and adjustment of pH are additional strategies currently under investigation. PMID:12826480

  7. IN-SITU BIOREMEDIATION OF METHYL TERTIARY BUTYL ETHER (MTBE) - ADVANCED FUEL HYDROCARBON REMEDIATION NATIONAL TEST LOCATION.

    EPA Science Inventory

    Equilon's Westhollow Technology Center teamed with Arizona State University to evaluate an in-situ process for bioremediation of methyl tertiary butyl ether (MTBE). MTBE is a gasoline additive that was introduced in fuels to reduce emission of a number of air pollutants including...

  8. PERFORMANCE OF ACTIVE IN SITU REMEDIAL TECHNOLOGY FOR TREATMENT OF MTBE AND BENZENE AT UST SOURCE AREAS IN KANSAS

    EPA Science Inventory

    Both MtBE and Benzene are present at over 86% of the Underground Storage Tank sites in Kansas, USA that require active remediation. In situ remedial technologies, consisting primarily of soil vapor extraction and air sparging, are the preferred choice for treatment for MtBE site...

  9. IDENTIFYING AND PREDICTING DIVING PLUME BEHAVIOR AT GROUNDWATER SITES CONTAINING MTBE: PART 1 SUPPLEMENTAL FUNDING FOR ACTIVITIES IN FY 2002

    EPA Science Inventory

    This work will complete work began under Identifying and Predicting Plume Diving Behavior at Groundwater Sites Containing MTBE: Part 1. As of September 2001, ORD Staff and ORD Contractors have characterized dividing MTBE plumes at Spring Green, Wisconsin; Milford, Michigan; and ...

  10. WATER QUALITY AT FIVE MARINAS IN LAKE TEXOMA AS RELATED TO METHYL TERT-BUTYL ETHER (MTBE)

    EPA Science Inventory

    Occurrence of methyl tert-butyl ether (MTBE) in five marinas was monitored between June 1999 and November 2000 in Lake Texoma located on the border of Oklahoma and Texas. MTBE is a commonly used gasoline additive and a suspected carcinogen. Lake water was collected at locations i...

  11. Methyl tert-butyl ether (MTBE) in public and private wells in New Hampshire: Occurrence, factors, and possible implications

    USGS Publications Warehouse

    Ayotte, J.D.; Argue, D.M.; McGarry, F.J.; Degnan, J.R.; Hayes, L.; Flanagan, S.M.; Helsel, D.R.

    2008-01-01

    Methyl tert-butyl ether (MTBE) concentrations ???0.2 ??g/L were found in samples of untreated water in 18% of public-supply wells (n = 284) and 9.1% of private domestic wells (n = 264) sampled in 2005 and 2006 in New Hampshire. In counties that used reformulated gasoline (RFG), MTBE occurred at or above 0.2 ??g/L in 30% of public- and 17% of private-supply wells. Additionally, 52% of public-supply wells collocated with fuel storage and 71% of mobile home park wells had MTBE. MTBE occurrence in public-supply wells was predicted by factors such as proximity to sources of fuel, land use, and population density, as well as low pH and distance from mapped lineaments. RFG use, land-use variables, and pH were important predictors of private-well MTBE occurrence. Variables representing sources of MTBE, such as the distance to known fuel sources, were not significant predictors of MTBE occurrence in private-supply wells. It is hypothesized that private wells may become contaminated from the collective effects of sources in high population areas and from undocumented incidental releases from onsite or proximal gasoline use. From 2003 to 2005, MTBE occurrence decreased in 63 public-supply wells and increased in 60 private-supply wells, but neither trend was statistically significant. ?? 2008 American Chemical Society.

  12. Methyl tert-butyl ether (MTBE) in public and private wells in New Hampshire: occurrence, factors, and possible implications.

    PubMed

    Ayotte, Joseph D; Argue, Denise M; McGarry, Frederick J; Degnan, James R; Hayes, Laura; Flanagan, Sarah M; Helsel, Dennis R

    2008-02-01

    Methyl tert-butyl ether (MTBE) concentrations > or = 0.2 /microg/L were found in samples of untreated water in 18% of public-supply wells (n = 284) and 9.1% of private domestic wells (n = 264) sampled in 2005 and 2006 in New Hampshire. In counties that used reformulated gasoline (RFG), MTBE occurred at or above 0.2 microg/L in 30% of public- and 17% of private-supply wells. Additionally, 52% of public-supply wells collocated with fuel storage and 71% of mobile home park wells had MTBE. MTBE occurrence in public-supply wells was predicted by factors such as proximity to sources of fuel, land use, and population density, as well as low pH and distance from mapped lineaments. RFG use, land-use variables, and pH were important predictors of private-well MTBE occurrence. Variables representing sources of MTBE, such as the distance to known fuel sources, were not significant predictors of MTBE occurrence in private-supply wells. It is hypothesized that private wells may become contaminated from the collective effects of sources in high population areas and from undocumented incidental releases from onsite or proximal gasoline use. From 2003 to 2005, MTBE occurrence decreased in 63 public-supply wells and increased in 60 private-supply wells, but neither trend was statistically significant. PMID:18323087

  13. Identifying the usage patterns of methyl tert-butyl ether (MTBE) and other oxygenates in gasoline using gasoline surveys

    USGS Publications Warehouse

    Moran, M.J.; Clawges, R.M.; Zogorski, J.S.

    2000-01-01

    Data on the volumes of oxygenates and other compounds in gasoline are available from several sources collectively referred as gasoline surveys. The gasoline surveys provide the most definitive knowledge of which oxygenate, if any, and what volumes of that oxygenate are being used in various areas of the country. This information is important in water-quality assessments for relating the detection of MTBE in water to patterns of usage of MTBE in gasoline. General information on three surveys that have been conducted by the National Institute for Petroleum and Energy Research, the Motor Vehicle Manufacturers Association, and the EPA was presented. The samples were tested for physical properties and constituents including octane number, specific gravity, and volumes of olefins, aromatics, benzene, alcohols, and various ether oxygenates. The data in each survey had its own utility based on the type of assessment that is undertaken. Quality Assessment (NAWQA) Program. Using NAWQA data, the percent occurrence of MTBE in ground water in metropolitan areas that use substantial amounts of MTBE (> 5% by vol) was ??? 21%, compared to ??? 2% in areas that do not use substantial amounts of MTBE (< 5% by vol). When several other factors are considered in a logistic regression model including MTBE usage in RFG or OXY gasoline areas (??? 3% by vol) as a factor, a 4-6 fold increase in the detection frequency of MTBE in ground water was found when compared to areas that do not use MTBE or use it only for octane enhancement (< 3% by vol).

  14. Identification of a Ruminococcaceae Species as the Methyl tert-Butyl Ether (MTBE) Degrading Bacterium in a Methanogenic Consortium.

    PubMed

    Liu, Tong; Ahn, Hyeri; Sun, Weimin; McGuinness, Lora R; Kerkhof, Lee J; Häggblom, Max M

    2016-02-01

    The widespread use of methyl tert-butyl ether (MTBE) has caused major contamination of groundwater sources and is a concern due to its taste and odor problems, as well as its toxicity. MTBE can be degraded anaerobically which makes bioremediation of contaminated aquifers a potential solution. Nevertheless, the organisms and mechanisms that are responsible for anaerobic MTBE degradation are still unknown. The aim of our research was to identify the organisms actively degrading MTBE. For this purpose we characterized an anaerobic methanogenic culture enriched with MTBE as the sole carbon source from the New Jersey Arthur Kill intertidal strait sediment. The cultures were analyzed using stable isotope probing (SIP) combined with terminal restriction fragment length polymorphism (T-RFLP), high-throughput sequencing and clone library analysis of bacterial 16S rRNA genes. The sequence data indicated that phylotypes belonging to the Ruminococcaceae in the Firmicutes were predominant in the methanogenic cultures. SIP experiments also showed sequential incorporation of the (13)C labeled MTBE by the bacterial community with a bacterium most closely related to Saccharofermentans acetigenes identified as the bacterium active in O-demethylation of MTBE. Identification of the microorganisms responsible for the activity will help us better understand anaerobic MTBE degradation processes in the field and determine biomarkers for monitoring natural attenuation. PMID:26727046

  15. Seasonal and daily variations in concentrations of methyl-tertiary-butyl ether (MTBE) at Cranberry Lake, New Jersey

    USGS Publications Warehouse

    Toran, L.; Lipka, C.; Baehr, A.; Reilly, T.; Baker, R.

    2003-01-01

    Methyl-tertiary-butyl ether (MTBE), an additive used to oxygenate gasoline, has been detected in lakes in northwestern New Jersey. This occurrence has been attributed to the use of gasoline-powered watercraft. This paper documents and explains both seasonal and daily variations in MTBE concentrations at Cranberry Lake. During a recent boating season (late April to September 1999), concentrations of MTBE typically exceeded 20??g/L. MTBE concentrations varied daily from 12 to 24??g/L over a 2-week period that included the Labor Day holiday. Concentrations were highest on weekends when there is more boat traffic, which had an immediate effect on MTBE mass throughout the lake. MTBE concentrations decreased to about 2??g/L shortly after the end of the summer recreational season. The loss of MTBE can be accounted for by volatilization, with a half-life on the order of 10 days. The volatilization rate was modeled with the daily decrease in MTBE then the modeled rate was validated using the data from the seasonal decline. ?? 2003 Elsevier Science Ltd. All rights reserved.

  16. DERMAL EXPOSURE TO METHYL TERT-BUTYL ETHER (MTBE) AND DIBROMOCHLOROMETHANE (DBCM) WHILE BATHING WITH CONTAMINATED WATER

    EPA Science Inventory

    The oxygenate methyl tert-butyl ether (MTBE) has been added to gasoline to help meet national ambient air quality standards in those parts of the U.S. that are non-compliant for carbon monoxide. Although MTBE has provided important health benefits in terms of reduced hazardous a...

  17. PHYSIOLOGICALLY-BASED PHARMACOKINETIC ( PBPK ) MODEL FOR METHYL TERTIARY BUTYL ETHER ( MTBE ): A REVIEW OF EXISTING MODELS

    EPA Science Inventory

    MTBE is a volatile organic compound used as an oxygenate additive to gasoline, added to comply with the 1990 Clean Air Act. Previous PBPK models for MTBE were reviewed and incorporated into the Exposure Related Dose Estimating Model (ERDEM) software. This model also included an e...

  18. REMOVAL OF METHYL T-BUTYL ETHER (MTBE) FROM WATER BY PERVAPORATION: BENCH-SCALE AND PILOT SCALE EVALUATIONS

    EPA Science Inventory

    The ability of pervaporation to remove methyl t-butyl ether (MTBE) from water was evaluated at bench- and pilot-scales. Process parameters studied included flow rate, temperature, MTBE concentration, membrane module type, and permeate pressure. Pervaporation performance was ass...

  19. PROPANE BIOSTIMULATIOIN BARRIER DEMONSTRATED IN MTBE-CONTAMINATED GROUND WATER

    EPA Science Inventory

    The U.S. EPA's National Risk Management Research Laboratory (NRMRL) and U.S. Navy recently completed a technology demonstration at the Naval Base Ventura County (NBVC) in Port Hueneme, CA. The demonstration was undertaken to determine whether biodegradation is reducing intrinsic...

  20. An adsorption-release-biodegradation system for simultaneous biodegradation of phenol and ammonium in phenol-rich wastewater.

    PubMed

    Wang, Ying; Chen, Hu; Liu, Yu-Xiang; Ren, Rui-Peng; Lv, Yong-Kang

    2016-07-01

    The feasibility of simultaneous biodegradation of phenol and ammonium in phenol-rich wastewater was evaluated in a reusable system, which contained macroporous adsorption resin and Alcaligenes faecalis strain WY-01. In the system, up to 6000mg/L phenol could be completely degraded by WY-01; meanwhile, 99.03±3.95% of ammonium was removed from the initial concentration of 384mg/L. This is the first study to show the capability of single strain in simultaneous removal of ammonium and phenol in wastewater containing such high concentrations of phenol. Moreover, the resin was regenerated during the biodegradation process without any additional manipulations, indicating the system was reusable. Furthermore, enzyme assay, gene expression patterns, HPLC-MS and gas chromatography analysis confirmed that phenol biodegradation accompanied with aerobic nitrifier denitrification process. Results imply that the reusable system provides a novel strategy for more efficient biodegradation of phenol and ammonium contained in some particular industrial wastewater. PMID:27060247

  1. Management of aerobic vaginitis.

    PubMed

    Tempera, Gianna; Furneri, Pio Maria

    2010-01-01

    Aerobic vaginitis is a new nonclassifiable pathology that is neither specific vaginitis nor bacterial vaginosis. The diversity of this microbiological peculiarity could also explain several therapeutic failures when patients were treated for infections identified as bacterial vaginosis. The diagnosis 'aerobic vaginitis' is essentially based on microscopic examinations using a phase-contrast microscope (at ×400 magnification). The therapeutic choice for 'aerobic vaginitis' should take into consideration an antibiotic characterized by an intrinsic activity against the majority of bacteria of fecal origin, bactericidal effect and poor/absent interference with the vaginal microbiota. Regarding the therapy for aerobic vaginitis when antimicrobial agents are prescribed, not only the antimicrobial spectrum but also the presumed ecological disturbance on the anaerobic and aerobic vaginal and rectal microbiota should be taken into a consideration. Because of their very low impact on the vaginal microbiota, kanamycin or quinolones are to be considered a good choice for therapy. PMID:21051843

  2. The risk of MTBE relative to other VOCs in public drinking water in California.

    PubMed

    Williams, Pamela R D; Benton, Laurie; Sheehan, Patrick J

    2004-06-01

    Ongoing publicity about methyl tertiary butyl ether (MTBE) suggests that this chemical is of greater concern than other contaminants commonly found in drinking water. The purpose of this article is to evaluate the available MTBE data in context with other volatile organic compounds (VOCs) that are detected in public drinking water sources in California. We find that of the 28 VOCs with a primary maximum contaminant level (MCL) in California, 21 were found in 50 or more drinking water sources from 1985 to 2002. Over the last 10 years, the most frequently detected VOCs were chloroform, tetrachloroethylene (PCE), and trichloroethylene (TCE), which were found in about 9-15% of all sampled drinking water sources. These same chemicals were found to have the highest mean detected concentrations over the last 5 years, ranging from 13 to 15 microg/L. Many VOCs were also found to routinely exceed state and federal drinking water standards, including benzene and carbon tetrachloride. By comparison, MTBE was found in approximately 1% of sampled drinking water sources for most years, and of those drinking water sources found to contain MTBE from 1998 to 2002, over 90% had detected concentrations below California's primary MCL of 13 microg/L. Relative to the other VOCs evaluated, MTBE has the lowest estimated California cancer potency value, and was found to pose one of the least cancer risks from household exposures to contaminated drinking water. These findings suggest that MTBE poses an insignificant threat to public drinking water supplies and public health in California, particularly when compared to other common drinking water contaminants. PMID:15209934

  3. Volatile Fuel Hydrocarbons and MTBE in the Environment

    NASA Astrophysics Data System (ADS)

    Cozzarelli, I. M.; Baehr, A. L.

    2003-12-01

    Petroleum hydrocarbons (hydrocarbons that result from petroleum products such as oil, gasoline, or diesel fuel) are among the most commonly occurring and widely distributed contaminants in the environment. Volatile hydrocarbons are the lighter fraction of the petroleum hydrocarbons and, together with fuel oxygenates, are most often released from crude oil and liquid petroleum products produced from crude oil. The demand for crude oil stems from the world's ever-growing energy need. From 1970 to 1999, primary energy production of the world grew by 76% (Energy Information Administration, 2001), with fossil fuels (crude oil, natural gas, and coal) accounting for ˜85% of all energy produced worldwide (Figure 1). World crude oil production reached a record 68 million barrels (bbl) per day (1.08×1010 L d-1) in 2000. The world's dependence on oil as an energy source clearly is identified as contributing to global warming and worsening air and water quality. (7K)Figure 1. World primary energy production by source from 1970 to 1999 (Energy Information Administration, 2001). Petroleum products are present in Earth's subsurface as solids, liquids, or gases. This chapter presents a summary of the environmental problems and issues related to the use of liquid petroleum, or oil. The focus is on the sources of volatile hydrocarbons and fuel oxygenates and the geochemical behavior of these compounds when they are released into the environment. Although oxygenates currently in commercial use include compounds other than methyl t-butyl ether (MTBE), such as ethanol (ETOH), most of the information presented here focuses on MTBE because of its widespread occurrence. The environmental impact of higher molecular weight hydrocarbons that also originate from petroleum products is described in (Chapter 9.13, Abrajano et al.).Crude oil occurs within the Earth and is a complex mixture of natural compounds composed largely of hydrocarbons containing only hydrogen and carbon atoms. The minor

  4. Biodegradation of a mixture of chlorinated volatile organic compounds

    SciTech Connect

    Barnes, L.J.W.; Daniel, S.R.; Warner, J.B.

    1997-12-31

    A mixture of vinyl chloride, cis- and trans-1,2-dichloroethene (DCE), and 1,1-dichloroethane (DCA) was biodegraded at 20 C in static microcosms by a consortium of indigenous microorganisms from a Superfund site contaminated with a variety of halogenated compounds. Microcosms were set up with sand and groundwater from the site to model biodegradation under aquifer conditions and biodegradation with various amendments in batch cultures. Under aerobic conditions, vinyl chloride and cis- and trans-1,2-DCE biodegraded slowly, although there was no change in the concentration of 1,1-DCA. The biodegradation rates for all three chlorinated ethenes were greatly increased by enriching for methanotrophs in an aerobic environment, but this had little effect on the concentration of 1,1-DCA. DCA and the dichloroethene isomers decreased. The rate at which 1,1-DCA decreased from the VOC mixture correlated directly to the concentration of the chlorinated ethenes in that mixture. This relationship may be new in the literature and has important implications for the potential success for intrinsic bioremediation of sites contaminated with mixtures of chlorinated compounds.

  5. Mathematical modeling of the effects of aerobic and anaerobic chelate bioegradation on actinide speciation.

    SciTech Connect

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

    1998-03-19

    Biodegradation of natural and anthropogenic chelating agents directly and indirectly affects the speciation, and, hence, the mobility of actinides in subsurface environments. We combined mathematical modeling with laboratory experimentation to investigate the effects of aerobic and anaerobic chelate biodegradation on actinide [Np(IV/V), Pu(IV)] speciation. Under aerobic conditions, nitrilotriacetic acid (NTA) biodegradation rates were strongly influenced by the actinide concentration. Actinide-chelate complexation reduced the relative abundance of available growth substrate in solution and actinide species present or released during chelate degradation were toxic to the organisms. Aerobic bio-utilization of the chelates as electron-donor substrates directly affected actinide speciation by releasing the radionuclides from complexed form into solution, where their fate was controlled by inorganic ligands in the system. Actinide speciation was also indirectly affected by pH changes caused by organic biodegradation. The two concurrent processes of organic biodegradation and actinide aqueous chemistry were accurately linked and described using CCBATCH, a computer model developed at Northwestern University to investigate the dynamics of coupled biological and chemical reactions in mixed waste subsurface environments. CCBATCH was then used to simulate the fate of Np during anaerobic citrate biodegradation. The modeling studies suggested that, under some conditions, chelate degradation can increase Np(IV) solubility due to carbonate complexation in closed aqueous systems.

  6. Manipulation of the HIF–Vegf pathway rescues methyl tert-butyl ether (MTBE)-induced vascular lesions

    SciTech Connect

    Bonventre, Josephine A.; Kung, Tiffany S.; White, Lori A.; Cooper, Keith R.

    2013-12-15

    Methyl tert-butyl ether (MTBE) has been shown to be specifically anti-angiogenic in piscine and mammalian model systems at concentrations that appear non-toxic in other organ systems. The mechanism by which MTBE targets developing vascular structures is unknown. A global transcriptome analysis of zebrafish embryos developmentally exposed to 0.00625–5 mM MTBE suggested that hypoxia inducible factor (HIF)-regulated pathways were affected. HIF-driven angiogenesis via vascular endothelial growth factor (vegf) is essential to the developing vasculature of an embryo. Three rescue studies were designed to rescue MTBE-induced vascular lesions: pooled blood in the common cardinal vein (CCV), cranial hemorrhages (CH), and abnormal intersegmental vessels (ISV), and test the hypothesis that MTBE toxicity was HIF–Vegf dependent. First, zebrafish vegf-a over-expression via plasmid injection, resulted in significantly fewer CH and ISV lesions, 46 and 35% respectively, in embryos exposed to 10 mM MTBE. Then HIF degradation was inhibited in two ways. Chemical rescue by N-oxaloylglycine significantly reduced CCV and CH lesions by 30 and 32% in 10 mM exposed embryos, and ISV lesions were reduced 24% in 5 mM exposed zebrafish. Finally, a morpholino designed to knock-down ubiquitin associated von Hippel–Lindau protein, significantly reduced CCV lesions by 35% in 10 mM exposed embryos. In addition, expression of some angiogenesis related genes altered by MTBE exposure were rescued. These studies demonstrated that MTBE vascular toxicity is mediated by a down regulation of HIF–Vegf driven angiogenesis. The selective toxicity of MTBE toward developing vasculature makes it a potentially useful chemical in the designing of new drugs or in elucidating roles for specific angiogenic proteins in future studies of vascular development. - Highlights: • Global gene expression of MTBE exposed zebrafish suggested altered HIF1 signaling. • Over expression of zebrafish vegf-a rescues MTBE

  7. Characterization of biodegraded coals

    SciTech Connect

    Bean, R.M.; Franz, J.A.; Campbell, J.C.; Linehan, J.C.; Stewart, D.L.; Thomas, B.L.

    1988-04-01

    We have been able to accomplish the biodegradation of bituminous Illinois No. 6 coal after a pretreatment consisting of air oxidation, using a culture of the fungus Penicillium sp. We report in this paper results of chemical and spectrometric analyses of the starting materials and products from Illinois No. 6 coal biodegradation, and compare the results with those previously reported from the biodegradation of leonardite. 13 refs., 1 fig., 5 tabs.

  8. 40 CFR 796.3100 - Aerobic aquatic biodegradation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... help to put toxic effects into perspective. (2) Definitions. (i) “Adaptation” is the process by which a... inoculum, including source, collection date, handling, storage and adaptation possibilities (i.e., that...

  9. 40 CFR 796.3100 - Aerobic aquatic biodegradation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... help to put toxic effects into perspective. (2) Definitions. (i) “Adaptation” is the process by which a... inoculum, including source, collection date, handling, storage and adaptation possibilities (i.e., that...

  10. Biodegradability of Plastics

    PubMed Central

    Tokiwa, Yutaka; Calabia, Buenaventurada P.; Ugwu, Charles U.; Aiba, Seiichi

    2009-01-01

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed. PMID:19865515

  11. Soil Physical Constraints on Intrinsic Biodegradation of Petroleum Vapors in a Layered Subsurface

    PubMed Central

    Kristensen, Andreas H.; Henriksen, Kaj; Mortensen, Lars; Scow, Kate M.; Moldrup, Per

    2011-01-01

    Naturally occurring biodegradation of petroleum hydrocarbons in the vadose zone depends on the physical soil environment influencing field-scale gas exchange and pore-scale microbial metabolism. In this study, we evaluated the effect of soil physical heterogeneity on biodegradation of petroleum vapors in a 16-m-deep, layered vadose zone. Soil slurry experiments (soil/water ratio 10:30 w/w, 25°C) on benzene biodegradation under aerobic and well-mixed conditions indicated that the biodegradation potential in different textured soil samples was related to soil type rather than depth, in the order: sandy loam > fine sand > limestone. Similarly, O2 consumption rates during in situ respiration tests performed at the site were higher in the sandy loam than in the fine sand, although the difference was less significant than in the slurries. Laboratory and field data generally agreed well and suggested a significant potential for aerobic biodegradation, even with nutrient-poor and deep subsurface conditions. In slurries of the sandy loam, the biodegradation potential declined with increasing in situ water saturation (i.e., decreasing air-filled porosity in the field). This showed a relation between antecedent undisturbed field conditions and the slurry biodegradation potential, and suggested airfilled porosity to be a key factor for the intrinsic biodegradation potential in the field. PMID:21617737

  12. Teaching Aerobic Lifestyles: New Perspectives.

    ERIC Educational Resources Information Center

    Goodrick, G. Ken; Iammarino, Nicholas K.

    1982-01-01

    New approaches to teaching aerobic life-styles in secondary schools are suggested, focusing on three components: (1) the psychological benefits of aerobic activity; (2) alternative aerobic programs at nonschool locations; and (3) the development of an aerobics curriculum to help maintain an active life-style after graduation. (JN)

  13. Preliminary assessment of the occurrence and possible sources of MTBE in groundwater in the United States, 1993-1994

    USGS Publications Warehouse

    Squillace, P.J.; Zogorski, J.S.; Wilber, W.G.; Price, C.V.

    1996-01-01

    The 1990 Clean Air Act Amendments require fuel oxygenates to be added to gasoline used in some metropolitan areas to reduce atmospheric concentrations of carbon monoxide or ozone. Methyl tert-butyl ether (MTBE) is the most commonly used fuel oxygenate and is a relatively new gasoline additive. Nevertheless, out of 60 volatile organic chemicals analyzed, MTBE was the second most frequently detected chemical in samples of shallow ambient groundwater from urban areas that were collected during 1993-1994 aspart of the U.S. Geological Survey's National Water-Quality Assessment program. Samples were collected from five drinking water wells, 12 springs, and 193 monitoring wells in urban areas. No MTBE was detected in drinking water wells. At a reporting level of 0.2 ??g/L, MTBE was detected most frequently in shallow groundwater from urban areas (27% of 210 wells and springs sampled in eight areas) as compared to shallow groundwater from agricultural areas (1.3% of 549 wells sampled in 21 areas) or deeper groundwater from major aquifers (1.0% of 412 wells sampled in nine areas). Only 3% of the shallow wells sampled in urban areas had concentrations of MTBE that exceed 20 ??g/L, which is the estimated lower limit of the United States Environmental Protection Agency draft drinking water health advisory. Because MTBE is persistent and mobile in groundwater, it can move from shallow to deeper aquifers with time. In shallow urban groundwater, MTBE generally was not found with benzene, toluene, ethylbenzene, or xylene (BTEX) compounds, which commonly are associated with gasoline spills. This disassociation causes uncertainty as to the source of MTBE. Possible sources of MTBE in groundwater include point sources, such as leaking storage tanks, and non-point sources, such as recharge of precipitation and stormwater runoff.

  14. Review of quantitative surveys of the length and stability of MTBE, TBA, and benzene plumes in groundwater at UST sites.

    PubMed

    Connor, John A; Kamath, Roopa; Walker, Kenneth L; McHugh, Thomas E

    2015-01-01

    Quantitative information regarding the length and stability condition of groundwater plumes of benzene, methyl tert-butyl ether (MTBE), and tert-butyl alcohol (TBA) has been compiled from thousands of underground storage tank (UST) sites in the United States where gasoline fuel releases have occurred. This paper presents a review and summary of 13 published scientific surveys, of which 10 address benzene and/or MTBE plumes only, and 3 address benzene, MTBE, and TBA plumes. These data show the observed lengths of benzene and MTBE plumes to be relatively consistent among various regions and hydrogeologic settings, with median lengths at a delineation limit of 10 µg/L falling into relatively narrow ranges from 101 to 185 feet for benzene and 110 to 178 feet for MTBE. The observed statistical distributions of MTBE and benzene plumes show the two plume types to be of comparable lengths, with 90th percentile MTBE plume lengths moderately exceeding benzene plume lengths by 16% at a 10-µg/L delineation limit (400 feet vs. 345 feet) and 25% at a 5-µg/L delineation limit (530 feet vs. 425 feet). Stability analyses for benzene and MTBE plumes found 94 and 93% of these plumes, respectively, to be in a nonexpanding condition, and over 91% of individual monitoring wells to exhibit nonincreasing concentration trends. Three published studies addressing TBA found TBA plumes to be of comparable length to MTBE and benzene plumes, with 86% of wells in one study showing nonincreasing concentration trends. PMID:25040137

  15. Aerobic Conditioning Class.

    ERIC Educational Resources Information Center

    Johnson, Neil R.

    1980-01-01

    An aerobic exercise class that focuses on the conditioning of the cardiovascular and muscular systems is presented. Students complete data cards on heart rate, pulse, and exercises to be completed during the forty minute course. (CJ)

  16. NOVEL EMBEDDED CERAMIC ELECTRODE SYSTEM TO ACTIVATE NANOSTRUCTURED TITANIUM DIOXIDE FOR DEGRADATION OF MTBE

    EPA Science Inventory

    A novel reactor combining a flame-deposited nanostructured titanium dioxide film and a set of embedded ceramic electrodes was designed, developed and tested for degradation of methyl tert-butyl ether (MTBE) in water. On applying a voltage to the ceramic electrodes, a surface coro...

  17. USING DIRECT-PUSH TOOLS TO MAP HYDROSTRATIGRAPHY AND PREDICT MTBE PLUME DIVING

    EPA Science Inventory

    Conventional wells for monitoring MTBE contamination at underground storage tank sites are screened a few feet above and a few feet below the water table. At some sites, a plume of contamination in ground water may dive below the screen of conventional monitoring wells and escap...

  18. HUMAN EXPOSURE TO METHYL TERTIARY BUTYL ETHER (MTBE) WHILE BATHING WITH CONTAMINATED WATER.

    EPA Science Inventory

    MTBE is a synthetic gasoline additive that has been found in a number of public drinking water systems in California and other states. Several of the highest concentrations have been found in drinking water wells in the City of Santa Monica, CA where levels as high as 610 ppb hav...

  19. IRIS Toxicological Review and Summary Documents for Methyl Tert-Butyl Ether (MTBE)

    EPA Science Inventory

    MTBE is a volatile organic chemical used to oxygenate gasoline. Oxygenated gasoline improves the exhaust emissions from gasoline engines. Since 1992 it has been used to comply with the Federal Reformulated Gasoline (begun in 1995) and Wintertime Oxygenated Fuel (begun in 1992) p...

  20. Particle Size Effects on Fenton Regeneration of MTBE-spent Activated Carbon

    EPA Science Inventory

    Fenton-driven regeneration of spent granular activated carbon (GAC) is a developing technology that may reduce water treatment costs. In this study, the effect of GAC particle size on Fenton-driven oxidation of methyl tert-butyl ether (MTBE)-spent GAC was evaluated. The GAC was...

  1. USING DIRECT-PUSH TOOLS TO MAP HYDROSTRATIGRAPHY AND PREDICT MTBE PLUME DIVING

    EPA Science Inventory

    MTBE plumes have been documented to dive beneath screened intervals of conventional monitoring well networks at a number of LUST sites. This behavior makes these plumes difficult both to detect and remediate. Electrical conductivity logging and pneumatic slug testing performed in...

  2. BTEX MTBE BIOREMEDIATION: BIONETS CONTAINING ISOLITE, PM1, SOLID OXYGEN SOURCE

    EPA Science Inventory

    Methyl tert-Butyl Ether (MTBE), a gasoline additive, is a persistent and foul tasting contaminate that is more mobile in ground water than BTEX . It, along with BTEX, is turning up at many American crossroads. This study's objective was to determine if biologically active in sit...

  3. MTBE BIOREMEDIATION WITH BIONETS CONTAINING ISOLITE®, PM1, SOLID OXYGEN SOURCE (SOS) OR AIR

    EPA Science Inventory

    MTBE, a gasoline additive, is a persistent and foul tasting contaminant that is more mobile in groundwater than BTEX (benzene, toluene, ethylbenzene, xylenes). It is turning up at many American crossroads. The objective of this well controlled study was to determine if biological...

  4. MTBE BIOREMEDIATION WITH BIONETS(TM) CONTAINING ISOLITE, PM1, SOLD OXYGEN SOURCE (SOS) OR AIR

    EPA Science Inventory

    MTBE, a gasoline additive, is a persistent and foul tasting contaminant that is more mobile in groundwater than BTEX (benzene, toluene, ethylbenzene, xylenes). It is turning up at many American crossroads. The objective of this well controlled study was to determine if biological...

  5. STABLE ISOTOPE ANALYSIS OF MTBE TO EVALUATE THE SOURCE OF TBA IN GROUND WATER

    EPA Science Inventory

    Although tert-butyl alcohol (TBA) has not been used as a fuel oxygenate in Orange County, California, the concentrations of TBA in ground water at gasoline spill sites are high compared those of the conventional fuel oxygenate methyl tert-butyl ether (MTBE). In the year 2002, th...

  6. DEMONSTRATION OF THE HIPOX ADVANCED OXIDATION TECHNOLOGY FOR THE TREATMENT OF MTBE-CONTAMINATED GROUNDWATER

    EPA Science Inventory

    The HiPOx technology is an advanced oxidation process that incorporates high-precision delivery of ozone and hydrogen peroxide to chemically destroy organic contaminants with the promise of minimizing bromate formation. A MTBE-contaminated groundwater from the Ventura County Nava...

  7. DEMONSTRATION OF THE HIPOX ADVANCED OXIDATION TECHNOLOGY FOR THE TREATMENT OF MTBE-CONTAMINATED GROUNDWATER

    EPA Science Inventory

    The HiPOx technology is an advanced oxidation process that incorporates high-precision delivery of ozone and hydrogen peroxide to chemically destroy organic contaminants with the promise of minimizing bromate formation. A MTBE-contaminated groundwater from the Ventura County Nav...

  8. REMOVAL OF METHYL TERTIARY BUTYL ETHER (MTBE) FROM GROUNDWATER USING PHOTOCATALYSIS

    EPA Science Inventory

    The potential of photocatalysis was determined for treating MTBE-contaminated drinking water supplies. Two liquid-phase systems, a falling film reactor, and a solar degradation system, are being evaluated. We are also conducting a gas-phase treatment method to simulate an integra...

  9. DERMAL, ORAL, AND INHALATION PHARMACOKINETICS OF METHYL TERTIARY BUTYL ETHER (MTBE) IN HUMAN VOLUNTEERS

    EPA Science Inventory

    Methyl tertiary butyl ether (MTBE), a gasoline additive, used to increase octane and reduce carbon monoxide emissions and ozone precursors has contaminated drinking water leading to exposure by oral, inhalation, and dermal routes. To determine its dermal, oral, and inhalation ki...

  10. DERMAL, ORAL AND INHALATION PHARMACOKINETICS OF METHYL TERTIARY-BUTYL ETHER (MTBE) IN HUMAN VOLUNTEERS

    EPA Science Inventory


    Methyl tertiary butyl ether (MTBE), a gasoline additive used to increase octane and reduce carbon monoxide emissions and ozone precursors, has contaminated drinking water and can lead to exposure by oral, inhalation, and dermal routes. To determine its dermal, oral, and inhal...

  11. Natural Attenuation of Chlorinated Solvents and Fuel Components (BTEX and MTBE) in Ground Water

    EPA Science Inventory

    Monitored Natural Attenuation is widely used in the USA to deal with ground water contamination from fuel components such as the BTEX compounds or MTBE or TBA and from chlorinated solvents such as PCE, TCE, and TCA. This presentation reviews the theory and practice of MNA in the...

  12. MONITORED NATURAL ATTENUATION AND RISK MANAGEMENT OF MTBE IN GROUND WATER (MONTEREY, CA)

    EPA Science Inventory

    Monitored natural attenuation (as U.S. EPA defines the term) is a remedy, where natural processes bring the concentration of MTBE to an acceptable level in a reasonable period of time. The longevity of the plume is its critical property. The rate of attenuation is typically con...

  13. MONITORED NATURAL ATTENUATION AND RISK MANAGEMENT OF MTBE IN GROUND WATER (LOS ANGELES, CA)

    EPA Science Inventory

    Monitored natural attenuation (as U.S. EPA defines the term) is a remedy, where natural processes bring the concentration of MTBE to an acceptable level in a reasonable period of time. The longevity of the plume is its critical property. The rate of attenuation is typically con...

  14. MONITORED NATURAL ATTENUATION AND RISK MANAGEMENT OF MTBE IN GROUND WATER

    EPA Science Inventory

    Monitored natural attenuation (as U.S. EPA defines the term) is a remedy, where natural processes bring the concentration of MTBE to an acceptable level in a reasonable period of time. The longevity of the plume is its critical property. The rate of attenuation is typically con...

  15. MONITORED NATURAL ATTENUATION AND RISK MANAGEMENT OF MTBE AND TBA IN GROUND WATER

    EPA Science Inventory

    Monitored natural attenuation (as U.S. EPA defines the term) is a remedy, where natural processes bring the concentration of MTBE or TBA to an acceptable level in a reasonable period of time. The longevity of the plume is its critical property. The rate of attenuation is typica...

  16. Advances in our knowledge of biodegradation of hydrocarbons in reservoirs

    SciTech Connect

    Connan, J. )

    1993-09-01

    Biodegradation of hydrocarbons in reservoirs is a widespread phenomenon that is currently observed by petroleum organic geochemists in most sedimentary basins. This basic phenomenon is responsible for the occurrence of large, heavy oil deposits referred to as tar mats or tar belts. Biodegradation of crude oils takes place in reservoirs in which oil-eating bacteria may thrive. For this reason, effective and present biodegradation effects are not observed at subsurface temperatures higher than 70-80[degrees]C. Significant compositional changes, especially at a molecular level, still remain linked to the aerobic biodegradation of crude oils. Under favorable circumstances, both alkanes and aromatics are degraded, but when nutrients (N, P, O[sup 2]) are impoverished, aromatics seem to be preferentially removed. Biodegradation extends also to sulfur-bearing aromatics with a preferential removal of alkylated structures. Changes in molecular patterns are used to assess degrees of biodegradation in crude oils. The most bacterially resistant structures are polycyclic alkanes and aromatics. The in-reservoir biodegradation of hydrocarbons does not generate new hydrocarbons, e.g., 25-norhopanes as proposed by several authors. In fact, the selective removal of less resistant structures concentrates preexisting minor families that were not detected on the unaltered crude due to their low absolute concentration. Consequently, the molecular spectrum found in severely biodegraded oils may be considered as highly diagnostic of a part of the primary genetic spectrum of each oil. In outcrop samples, biodegradation is associated with other complementary phenomena such as photooxidation, oxidation, inspissation, evaporation, water washing, etc. Of particular importance are weathering effects linked to oxidation, which entail drastic compositional changes, with neogenesis of resins, asphaltenes, and even insoluble residue.

  17. Biodegradation of chlorinated and non-chlorinated VOCs from pharmaceutical industries.

    PubMed

    Balasubramanian, P; Philip, Ligy; Bhallamudi, S Murty

    2011-02-01

    Biodegradation studies were conducted for major organic solvents such as methanol, ethanol, isopropanol, acetone, acetonitrile, toluene, chloroform, and carbon tetrachloride commonly used in pharmaceutical industries. Various microbial isolates were enriched and screened for their biodegradation potential. An aerobic mixed culture that had been previously enriched for biodegradation of mixed pesticides was found to be the most effective. All the organic solvents except chloroform and carbon tetrachloride were consumed as primary substrates by this mixed culture. Biodegradation rates of methanol, ethanol, isopropanol, acetone, acetonitrile, and toluene were measured individually in batch systems. Haldane model was found to best fit the kinetics of biodegradation. Biokinetic parameters estimated from single-substrate experiments were utilized to simulate the kinetics of biodegradation of mixture of substrates. Among the various models available for simulating the kinetics of biodegradation of multi-substrate systems, competitive inhibition model performed the best. Performance of the models was evaluated statistically using the dimensionless modified coefficient of efficiency (E). This model was used for simulating the kinetics of biodegradation in binary, ternary, and quaternary substrate systems. This study also reports batch experiments on co-metabolic biodegradation of chloroform, with acetone and toluene as primary substrates. The Haldane model, modified for inhibition due to chloroform, could satisfactorily predict the biodegradation of primary substrate, chloroform, and the microbial growth. PMID:20799072

  18. Simulations of Flow, Transport, and Biodegradation in Landfills

    NASA Astrophysics Data System (ADS)

    Oldenburg, C. M.; Borglin, S. E.; Hazen, T. C.

    2002-12-01

    Biotreatment of landfill materials may involve coupled nonisothermal flow and transport of water and gas in the refuse mass. With the objective of carrying out analyses that depend on flow and transport processes, we are developing T2LBM, a module for the TOUGH2 multiphase flow and transport simulator that implements a Landfill Bioreactor Model. T2LBM models the processes of aerobic and anaerobic biodegradation of municipal solid waste and the associated three-dimensional flow and transport of gas, liquid, and heat through the refuse mass. The components modeled in T2LBM are water, acetic acid, carbon dioxide, methane, oxygen, and nitrogen in aqueous and gas phases, with partitioning specified by temperature-dependent Henry's coefficients. The local oxygen concentration is used to control whether aerobic or anaerobic biodegradation reactions occur to produce carbon dioxide, or methane and carbon dioxide, respectively. Acetic acid is used as a proxy for all of the biodegradable components in the refuse. The biodegradation rate of acetic acid is modeled using a Monod kinetic rate law for the exothermic reactions in the aqueous phase. The compaction rate is specified by the user and modeled as a linear decrease with time of porosity and contraction of the vertical grid dimension by generation of a new grid at each time step. Local differences in moisture content, pressure, gas composition, aerobicity, and temperature, among other properties, within the heterogeneous refuse can be modeled with T2LBM. Comparison of simulation results against observations of an aerobic landfill bioreactor laboratory experiment and an anaerobic field pilot study show good agreement for oxygen consumption and gas production. Predictions and sensitivity analyses of different biotreatments can be made using this new simulation capability. This work was supported by Laboratory Directed Research and Development Funds at Lawrence Berkeley National Laboratory under Department of Energy Contract

  19. MTBE Hydrolysis in Dilute Aqueous Solution Using Heterogeneous Strong Acid Catalysts

    NASA Astrophysics Data System (ADS)

    Rixey, W. G.

    2003-12-01

    The objective of this research has been the development of a potential in situ catalytic process for the hydrolysis of methyl tertiary butyl ether (MTBE) to tertiary butyl alcohol (TBA) and methanol in ground water. Bench-scale batch reactor studies were conducted over a temperature range of 23 deg C to 50 deg C with several heterogeneous strong acid catalysts to obtain rates of hydrolysis of MTBE to TBA and methanol at dilute concentrations in water. Continuous flow experiments were then conducted to obtain kinetic data over a temperature range of 15 deg C to 50 deg C for various flow rates for the most active catalysts. It was found that the batch and continuous flow experiments yielded similar intrinsic kinetic rate constants when sorption of MTBE to the catalyst was accounted for. Additional fixed-bed experiments were conducted with deionized water and 0.005 M CaCl2 feed solutions containing 100 mg/L MTBE, respectively, to assess the deactivation of the catalyst, and deactivation was found to be controlled by ion exchange of H+ in the catalyst with Ca+2 in the feed. Our results indicate that, for low to moderate groundwater velocities and cation concentrations at ambient temperatures, an in situ reactive barrier process using the most active catalysts studied in this research could be a viable process in terms of both suitable conversion of MTBE and catalyst life. Although application to in situ remediation is emphasized, the results of this research are also applicable to ex-situ groundwater treatment.

  20. Long-term evolution of biodegradation and volatilization rates in a crude oil-contaminated aquifer

    USGS Publications Warehouse

    Chaplin, B.P.; Delin, G.N.; Baker, R.J.; Lahvis, M.A.

    2002-01-01

    Volatilization and subsequent biodegradation near the water Table make up a coupled natural attenuation pathway that results in significant mass loss of hydrocarbons. Rates of biodegradation and volatilization were documented twice 12 years apart at a crude-oil spill site near Bemidji, Minnesota. Biodegradation rates were determined by calibrating a gas transport model to O2, CO2, and CH4 gas-concentration data in the unsaturated zone. Reaction stoichiometry was assumed in converting O2 and CO2 gas-flux estimates to rates of aerobic biodegradation and CH4 gas-flux estimates to rates of methanogenesis. Model results indicate that the coupled pathway has resulted in significant hydrocarbon mass loss at the site, and it was estimated that approximately 10.52 kg/day were lost in 1985 and 1.99 kg/day in 1997. In 1985 3% of total volatile hydrocarbons diffusing from the floating oil were biodegraded in the lower 1 m of the unsaturated zone and increased to 52% by 1997. Rates of hydrocarbon biodegradation above the center of the floating oil were relatively stable from 1985 to 1997, as the primary metabolic pathway shifted from aerobic to methanogenic biodegradation. Model results indicate that in 1997 biodegradation under methanogenenic conditions represented approximately one-half of total hydrocarbon biodegradation in the lower 1 m of the unsaturated zone. Further downgradient, where substrate concentrations have greatly increased, total biodegradation rates increased by greater than an order of magnitude from 0.04 to 0.43 g/m2-day. It appears that volatilization is the primary mechanism for attenuation in early stages of plume evolution, while biodegradation dominates in later stages.

  1. Process Modeling of Flow, Transport, and Biodegradation in Landfill Bioreactors

    NASA Astrophysics Data System (ADS)

    Oldenburg, C. M.; Borglin, S. E.; Hazen, T. C.

    2001-12-01

    The need to control gas and leachate production and minimize refuse volume has motivated laboratory experiments and model development for design and assessment of bioremediation treatment processes. In parallel with landfill bioreactor laboratory experiments, we have developed T2LBM, a module for the TOUGH2 multiphase flow and transport simulator that implements a Landfill Bioreactor Model. T2LBM provides simulation capability for the processes of aerobic or anaerobic biodegradation of municipal solid waste and the associated three-dimensional flow and transport of gas, liquid, and heat through the refuse mass. T2LBM considers the components water, acetic acid, carbon dioxide, methane, oxygen, and nitrogen in aqueous and gas phases, with partitioning specified by temperature-dependent Henry's coefficients. T2LBM incorporates a Monod kinetic rate law for the exothermic biodegradation of acetic acid in the aqueous phase by either aerobic or anaerobic microbes as controlled by the local oxygen concentration. Methane and carbon dioxide generation due to biodegradation with corresponding thermal effects are modeled. Acetic acid is considered a proxy for all biodegradable substrates in the refuse. Aerobic and anaerobic microbes are assumed to be immobile and not limited by nutrients in their growth. Although a simplification of complex landfill processes, T2LBM shows reasonable agreement to published laboratory experiments of biodegradation and gas production depending on the choice of numerous input parameters. Simulations of the landfill bioreactor laboratory experiments show that the mechanistic approach of T2LBM can be used to model bioremediation assessment indicators such as oxygen consumption associated with respiration tests. This work was supported by Laboratory Directed Research and Development Funds at Lawrence Berkeley National Laboratory under Department of Energy Contract No. DE-AC03-76SF00098.

  2. Analysis of dissolved benzene plumes and methyl tertiary butyl ether (MTBE) plumes in ground water at leaking underground fuel tank (LUFT) sites

    SciTech Connect

    Happel, A.M.; Rice, D.; Beckenbach, E.; Savalin, L.; Temko, H.; Rempel, R.; Dooher, B.

    1996-11-01

    The 1990 Clean Air Act Amendments mandate the addition of oxygenates to gasoline products to abate air pollution. Currently, many areas of the country utilize oxygenated or reformulated fuel containing 15- percent and I I-percent MTBE by volume, respectively. This increased use of MTBE in gasoline products has resulted in accidental point source releases of MTBE containing gasoline products to ground water. Recent studies have shown MTBE to be frequently detected in samples of shallow ground water from urban areas throughout the United States (Squillace et al., 1995). Knowledge of the subsurface fate and transport of MTBE in ground water at leaking underground fuel tank (LUFT) sites and the spatial extent of MTBE plumes is needed to address these releases. The goal of this research is to utilize data from a large number of LUFT sites to gain insights into the fate, transport, and spatial extent of MTBE plumes. Specific goals include defining the spatial configuration of dissolved MTBE plumes, evaluating plume stability or degradation over time, evaluating the impact of point source releases of MTBE to ground water, and attempting to identify the controlling factors influencing the magnitude and extent of the MTBE plumes. We are examining the relationships between dissolved TPH, BTEX, and MTBE plumes at LUFT sites using parallel approaches of best professional judgment and a computer-aided plume model fitting procedure to determine plume parameters. Here we present our initial results comparing dissolved benzene and MTBE plumes lengths, the statistical significance of these results, and configuration of benzene and MTBE plumes at individual LUFT sites.

  3. Enhanced biodegradation by hydraulic heterogeneities in petroleum hydrocarbon plumes

    NASA Astrophysics Data System (ADS)

    Bauer, Robert D.; Rolle, Massimo; Bauer, Sebastian; Eberhardt, Christina; Grathwohl, Peter; Kolditz, Olaf; Meckenstock, Rainer U.; Griebler, Christian

    2009-02-01

    In case of dissolved electron donors and acceptors, natural attenuation of organic contaminant plumes in aquifers is governed by hydrodynamic mixing and microbial activity. Main objectives of this work were (i) to determine whether aerobic and anaerobic biodegradation in porous sediments is controlled by transverse dispersion, (ii) to elucidate the effect of sediment heterogeneity on mixing and biodegradation, and (iii) to search for degradation-limiting factors. Comparative experiments were conducted in two-dimensional sediment microcosms. Aerobic toluene and later ethylbenzene degradation by Pseudomonas putida strain F1 was initially followed in a plume developing from oxic to anoxic conditions and later under steady-state mixing-controlled conditions. Competitive anaerobic degradation was then initiated by introduction of the denitrifying strain Aromatoleum aromaticum EbN1. In homogeneous sand, aerobic toluene degradation was clearly controlled by dispersive mixing. Similarly, under denitrifying conditions, microbial activity was located at the plume's fringes. Sediment heterogeneity caused flow focusing and improved the mixing of reactants. Independent from the electron accepting process, net biodegradation was always higher in the heterogeneous setting with a calculated efficiency plus of 23-100% as compared to the homogeneous setup. Flow and reactive transport model simulations were performed in order to interpret and evaluate the experimental results.

  4. Volatile Fuel Hydrocarbons and MTBE in the Environment

    NASA Astrophysics Data System (ADS)

    Cozzarelli, I. M.; Baehr, A. L.

    2003-12-01

    Petroleum hydrocarbons (hydrocarbons that result from petroleum products such as oil, gasoline, or diesel fuel) are among the most commonly occurring and widely distributed contaminants in the environment. Volatile hydrocarbons are the lighter fraction of the petroleum hydrocarbons and, together with fuel oxygenates, are most often released from crude oil and liquid petroleum products produced from crude oil. The demand for crude oil stems from the world's ever-growing energy need. From 1970 to 1999, primary energy production of the world grew by 76% (Energy Information Administration, 2001), with fossil fuels (crude oil, natural gas, and coal) accounting for ˜85% of all energy produced worldwide (Figure 1). World crude oil production reached a record 68 million barrels (bbl) per day (1.08×1010 L d-1) in 2000. The world's dependence on oil as an energy source clearly is identified as contributing to global warming and worsening air and water quality. (7K)Figure 1. World primary energy production by source from 1970 to 1999 (Energy Information Administration, 2001). Petroleum products are present in Earth's subsurface as solids, liquids, or gases. This chapter presents a summary of the environmental problems and issues related to the use of liquid petroleum, or oil. The focus is on the sources of volatile hydrocarbons and fuel oxygenates and the geochemical behavior of these compounds when they are released into the environment. Although oxygenates currently in commercial use include compounds other than methyl t-butyl ether (MTBE), such as ethanol (ETOH), most of the information presented here focuses on MTBE because of its widespread occurrence. The environmental impact of higher molecular weight hydrocarbons that also originate from petroleum products is described in (Chapter 9.13, Abrajano et al.).Crude oil occurs within the Earth and is a complex mixture of natural compounds composed largely of hydrocarbons containing only hydrogen and carbon atoms. The minor

  5. Metabolism of 2-Methylpropene (Isobutylene) by the Aerobic Bacterium Mycobacterium sp. Strain ELW1

    PubMed Central

    Kottegoda, Samanthi; Waligora, Elizabeth

    2015-01-01

    An aerobic bacterium (Mycobacterium sp. strain ELW1) that utilizes 2-methylpropene (isobutylene) as a sole source of carbon and energy was isolated and characterized. Strain ELW1 grew on 2-methylpropene (growth rate = 0.05 h−1) with a yield of 0.38 mg (dry weight) mg 2-methylpropene−1. Strain ELW1 also grew more slowly on both cis- and trans-2-butene but did not grow on any other C2 to C5 straight-chain, branched, or chlorinated alkenes tested. Resting 2-methylpropene-grown cells consumed ethene, propene, and 1-butene without a lag phase. Epoxyethane accumulated as the only detected product of ethene oxidation. Both alkene consumption and epoxyethane production were fully inhibited in cells exposed to 1-octyne, suggesting that alkene oxidation is initiated by an alkyne-sensitive, epoxide-generating monooxygenase. Kinetic analyses indicated that 1,2-epoxy-2-methylpropane is rapidly consumed during 2-methylpropene degradation, while 2-methyl-2-propen-1-ol is not a significant metabolite of 2-methylpropene catabolism. Degradation of 1,2-epoxy-2-methylpropane by 2-methylpropene-grown cells led to the accumulation and further degradation of 2-methyl-1,2-propanediol and 2-hydroxyisobutyrate, two sequential metabolites previously identified in the aerobic microbial metabolism of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Growth of strain ELW1 on 2-methylpropene, 1,2-epoxy-2-methylpropane, 2-methyl-1,2-propanediol, and 2-hydroxyisobutyrate was fully inhibited when cobalt ions were omitted from the growth medium, while growth on 3-hydroxybutyrate and other substrates was unaffected by the absence of added cobalt ions. Our results suggest that, like aerobic MTBE- and TBA-metabolizing bacteria, strain ELW1 utilizes a cobalt/cobalamin-dependent mutase to transform 2-hydroxyisobutyrate. Our results have been interpreted in terms of their impact on our understanding of the microbial metabolism of alkenes and ether oxygenates. PMID:25576605

  6. Biodegradation potential of a modified natural product

    SciTech Connect

    Sajjad, W.

    1996-12-31

    Biodegradation potential of a modified natural product for treating petroleum contaminated soils was investigated along with some commercially available microbial cultures in three different scales from a laboratory to pilot to case studies. The modified natural product is lignocellulosic in nature and proprietary product of a company in Iowa. The production process of this product involves mechanical size reduction, blending/coating, and aerobic digestion of hay, corn cob residue, straw or crop residue in presence of poultry manure. The degradation kinetics of the petroleum products in the contaminated soils were measured both directly and indirectly. Residual petroleum products in different soils (treated and untreated) at various time periods were quantified by gas chromatographic (GC) analysis on extracted samples. The indirect assessment of the kinetics of biological activity involved the measurement of CO{sub 2} evolved from flasks (250 ml capacity) containing contaminated soil (about 50 ml) with various treatments. The results indicated that the biodegradation kinetics of petroleum products in the contaminated soils were significantly improved by treatment with this modified natural product. In most cases tested, this product performed significantly better than the available commercial bacterial cultures for biological removal of petroleum products from contaminated soils. This study also demonstrated the significance of temperature and moisture content in biodegradation kinetics.

  7. Biodegradation potential of photocatalyzed surfactant washwater.

    PubMed

    Maillacheruvu, K; Buck, L; Lee, E

    2001-01-01

    Enhanced release of hydrophobic compounds from a soil matrix can be achieved by use of soil-washing or soil-flushing using various surfactants. However, the surfactants used in achieving the desorption of organic contaminants may also cause a problem in subsequent removal/disposal of these contaminants. UV radiation in the presence of TiO2 as a pre-treatment step to achieve initial (or partial) breakdown of naphthalene and Sodium Dodecyl Sulfate (SDS) using batch experiments indicated that 56% to 88% naphthalene degradation occurred within 30 minutes to one hour. Preliminary results on the estimate of the batch aerobic biodegradation potential of photocatalyzed washwater containing naphthalene and SDS suggested that SDS was the major carbon and energy source for an activated sludge enrichment culture and an enrichment culture obtained from microorganisms at a contaminated site. Continuous-flow stirred tank reactors (CSTRs) with with a solids retention time (SRT) of 4 days were not effective, but an SRT of 8 days was successful in biodegrading the naphthalene and surfactant. These results indicated that photocatalytic treatment as a pre-treatment step followed by a biodegradation step may offer potential in cleaning up surfactant washwaters containing organic contaminants. PMID:11501312

  8. Biodegradation of disinfection byproducts as a potential removal process during aquifer storage recovery

    USGS Publications Warehouse

    Landmeyer, J.E.; Bradley, P.M.; Thomas, J.M.

    2000-01-01

    The biodegradation potential of two drinking water disinfection byproducts was investigated using aquifer materials obtained from approximately 100 and 200 meters below land surface in an aerobic aquifer system undergoing aquifer storage recovery of treated surface water. No significant biodegradation of a model trihalomethane compound, chloroform, was observed in aquifer microcosms under aerobic or anaerobic conditions. In contrast, between 16 and 27 percent mineralization of a radiolabeled model haloacetic acid compound, chloroacetic acid, was observed. These results indicate that although the potential for biodegradation of chloroacetic acid exists in deep aquifer systems, chloroform entrained within these aquifers or formed in situ will tend to persist. These results have important implications for water managers planning to meet anticipated lowered permissible levels of tri-halomethanes in drinking water.The biodegradation potential of two drinking water disinfection byproducts was investigated using aquifer materials obtained from approximately 100 and 200 meters below land surface in an aerobic aquifer system undergoing aquifer storage recovery of treated surface water. No significant biodegradation of a model trihalomethane compound, chloroform, was observed in aquifer microcosms under aerobic or anaerobic conditions. In contrast, between 16 and 27 percent mineralization of a radiolabeled model haloacetic acid compound, chloroacetic acid, was observed. These results indicate that although the potential for biodegradation of chloroacetic acid exists in deep aquifer systems, chloroform entrained within these aquifers or formed in situ will tend to persist. These results have important implications for water managers planning to meet anticipated lowered permissible levels of trihalomethanes in drinking water.Aquifer-storage-recovery injection water often contains disinfection byproducts. Results are presented from a study in which two model disinfection

  9. Two-year drinking water carcinogenicity study of methyl tertiary-butyl ether (MTBE) in Wistar rats.

    PubMed

    Dodd, Darol; Willson, Gabrielle; Parkinson, Horace; Bermudez, Edilberto

    2013-07-01

    Methyl tertiary-butyl ether (MTBE) has been used as a gasoline additive to reduce tailpipe emissions and its use has been discontinued. There remains a concern that drinking water sources have been contaminated with MTBE. A two-year drinking water carcinogenicity study of MTBE was conducted in Wistar rats (males, 0, 0.5, 3, 7.5 mg ml(-1); and females, 0, 0.5, 3, and 15 mg ml(-1)). Body weights were unaffected and water consumption was reduced in MTBE-exposed males and females. Wet weights of male kidneys were increased at the end of two years of exposure to 7.5 mg ml(-1) MTBE. Chronic progressive nephropathy was observed in males and females, was more severe in males, and was exacerbated in the high MTBE exposure groups. Brain was the only tissue with a statistically significant finding of neoplasms. One astrocytoma (1/50) was found in a female rat (15 mg ml(-1)). The incidence of brain astrocytomas in male rats was 1/50, 1/50, 1/50 and 4/50 for the 0, 0.5, 3 and 7.5 mg ml(-1) exposure groups, respectively. This was a marginally significant statistical trend, but not statistically significant when pairwise comparisons were made or when multiple comparisons were taken into account. The incidence of astrocytoma fell within historical control ranges for Wistar rats, and the brain has not been identified as a target organ following chronic administration of MTBE, ethyl tert-butyl ether, or tertiary butyl alcohol (in drinking water) to mice and rats. We conclude that the astrocytomas observed in this study are not associated with exposure to MTBE. PMID:22161475

  10. Occurrence of the gasoline oxygenate MTBE and BTEX compounds in municipal stormwater in the United States, 1991-95

    USGS Publications Warehouse

    Delzer, G.C.; Zogorski, J.S.; Lopes, T.J.

    1997-01-01

    The U.S. Geological Survey (USGS) sampled stormwater in 16 cities and metropolitan areas that are required to obtain permits to discharge stormwater from their municipal storm-sewer system into surface water. Concentrations of 62 volatile organic compounds (VOCs), including methyl tert-butyl ether (MTBE) and BTEX (benzene, toluene, ethylbenzene, and total xylene) compounds, were measured in 592 stormwater samples collected in these cities and metropolitan areas from 1991 through 1995. MTBE was the seventh most frequently detected VOC in municipal stormwater. In decreasing order, the most frequently detected VOCs were toluene, total xylene, chloroform, total trimethylbenzene, tetrachloroethene, and naphthalene. MTBE was detected in 6.9 percent (41 of 592) of stormwater samples collected. When detected, concentrations of MTBE ranged from 0.2 to 8.7 micrograms per liter (??g/L), with a median of 1.5 ??g/L. All detections of MTBE were less than the lower limit of the U.S. Environmental Protection Agency's (USEPA) draft drinking water lifetime health advisory (20 ??g/L). Eighty-three percent of all detections of MTBE in stonnwater were in samples collected during October through March of each year (1991-95), which corresponds with the expected seasonal use of oxygenated gasoline in areas where carbon monoxide exceeds established air-quality standards. The median concentration of MTBE and benzene for all samples was statistically different and higher in samples collected during October through March than samples collected during April through September. Sixty-six percent of all MTBE: detections occurred with BTEX compounds, and a proportionate increase in concentrations was found when these compounds occurred together. Detected concentrations of toluene and total xylene ranged from 0.2 to 6.6 ??g/L and 0.2 to 15 ??g/L with median concentrations of 0.3 and 0.4 ??g/L, respectively.

  11. The impact of groundwater quality on the removal of methyl tertiary-butyl ether (MTBE) using advanced oxidation technology.

    PubMed

    Tawabini, B; Fayad, N; Morsy, M

    2009-01-01

    In this study, the removal of methyl tertiary-butyl ether (MTBE) from contaminated groundwater using advanced oxidation technology was investigated. The UV/H(2)O(2) treatment process was applied to remove MTBE from two Saudi groundwater sources that have different quality characteristics with regard to their contents of inorganic species such as chloride, bromide, sulfates and alkalinity. MTBE was spiked into water samples collected from the two sources to a concentration level of about 250 microg/L. A 500 mL bench-scale forced-liquid circulation photoreactor was used to conduct the experiments. Two different UV lamps were utilized: 15 Watt low pressure (LP) and 150 Watt medium pressure (MP). Results of the study showed that the UV/H(2)O(2) process removed more than 90% of MTBE in 20 minutes when the MP lamp was used at an MTBE/H(2)O(2) molar ratio of 1:200. The results also showed that groundwater sources with higher levels of radical scavengers such as alkalinity, bromide, nitrate and sulfate showed lower rate of MTBE removal. PMID:19844063

  12. Interdisciplinary investigation of subsurface contaminant transport and fate at point-source releases of gasoline containing MTBE

    SciTech Connect

    Buxton, H.T.; Baehr, A.L.; Landmeyer, J.E.

    1997-12-31

    Methyl tert-butyl ether (MTBE) is commonly found at concentrations above the current U.S. Environmental Protection Agency draft lifetime health advisory for drinking water (20 to 200 micrograms per liter) at many point-source gasoline release sites. MTBE is significantly more persistent than benzene, toluene, ethyl-benzene and xylenes (BTEX) in the subsurface. Therefore, evaluation of the implications of its presence in gasoline to monitored natural attenuation and engineered bioremediation alternatives is warranted. An interdisciplinary, field-based investigation of the subsurface transport and fate of MTBE and petroleum hydrocarbons is being conducted by the U.S. Geological Survey (USGS) Toxic Substances Hydrology Program at the site of an underground gasoline storage-tank release near Beaufort, South Carolina. The objective of the investigation is to provide a systematic evaluation of natural attenuation of MTBE compared to BTEX. Results of the field and laboratory studies at this site will be generalized to a broader range of hydrogeochemical conditions through experiments at other sites. Furthermore, newly developed methods of analysis can be applied to sites across the Nation. This investigation of MTBE at point-source release sites is coordinated with investigations of the occurrence of MTBE in shallow ground water, surface water, precipitation, and the atmosphere being conducted by the USGS National Water-Quality Assessment Program.

  13. Characterization of biodegraded coals

    SciTech Connect

    Bean, R.M.; Franz, J.A.; Campbell, J.A.; Linehan, J.C.; Stewart, D.L.; Thomas, B.L.

    1988-01-01

    Microbial degradation of coals to materials that are soluble in water has been a topic of intensive research for the last few years. The potential for economical recovery of low-grade coals, coupled with possibilities for further upgrading by microbial desulfurization or methanation has spurred intensive research at a number of laboratories. Until very recently, coal biodegradation has been accomplished using low-grade, naturally oxidized coals such as leonardiate, or coals subjected to pretreatment with oxidizing chemicals. The authors have been able to accomplish the biodegradation of bituminous Illinois 6 coal after a pretreatment consisting of air oxidation, using a culture of the fungus Penicillium sp. They report in this paper results of chemical and spectrometric analyses of the starting materials and products from Illinois 6 coal biodegradation, and compare the results with those previously reported from the biodegradation of leonardite.

  14. Dance--Aerobic and Anaerobic.

    ERIC Educational Resources Information Center

    Cohen, Arlette

    1984-01-01

    This article defines and explains aerobic exercise and its effects on the cardiovascular system. Various studies on dancers are cited indicating that dance is an anaerobic activity with some small degree of aerobic benefit. (DF)

  15. Anaerobic biodegradation of surrogate naphthenic acids.

    PubMed

    Clothier, Lindsay N; Gieg, Lisa M

    2016-03-01

    Surface bitumen extraction from the Alberta's oil sands region generates large settling basins known as tailings ponds. The oil sands process-affected water (OSPW) stored in these ponds contain solid and residual bitumen-associated compounds including naphthenic acids (NAs) that can potentially be biodedgraded by indigenous tailings microorganisms. While the biodegradation of some NAs is known to occur under aerobic conditions, little is understood about anaerobic NA biodegradation even though tailings ponds are mainly anoxic. Here, we investigated the potential for anaerobic NA biodegradation by indigenous tailings microorganisms. Enrichment cultures were established from anoxic tailings that were amended with 5 single-ringed surrogate NAs or acid-extractable organics (AEO) from OSPW and incubated under nitrate-, sulfate-, iron-reducing, and methanogenic conditions. Surrogate NA depletion was observed under all anaerobic conditions tested to varying extents, correlating to losses in the respective electron acceptor (sulfate or nitrate) or the production of predicted products (Fe(II) or methane). Tailings-containing cultures incubated under the different electron-accepting conditions resulted in the enrichment and putative identification of microbial community members that may function in metabolizing surrogate NAs under the various anoxic conditions. In addition, more complex NAs (in the form of AEO) was observed to drive sulfate and iron reduction relative to controls. Overall, this study has shown that simple surrogate NAs can be biodegraded under a variety of anoxic conditions, a key first step in understanding the potential anaerobic metabolism of NAs in oil sands tailings ponds and other industrial wastewaters. PMID:26724449

  16. MTBE, methane, ethylene and regulated exhaust emissions from vehicles with deactivated catalytic converters

    NASA Astrophysics Data System (ADS)

    Poulopoulos, S. G.; Philippopoulos, C. J.

    In the present work, the effect of the gradual deactivation of a three-way catalytic converter on the exhaust emissions was studied. The exhaust gases were analyzed for CO, HC (i.e. total unburned organic compounds), MTBE, methane and ethylene, before and after their catalytic treatment, in a wide range of engine operating conditions. The thermal aging of the catalytic converter resulted in an increase in the required time for the start of its operation and loss of its auto thermal operation. The catalytic efficiency was significantly decreased after each thermal aging step, especially at idle conditions. As a result, CO and especially HC emissions were increased, whereas ethylene and MTBE emissions were multiplied by a factor of 6-7 at 3.81 hp, in the case of the deactivated catalyst.

  17. Aerobic Anoxygenic Phototrophic Bacteria

    PubMed Central

    Yurkov, Vladimir V.; Beatty, J. Thomas

    1998-01-01

    The aerobic anoxygenic phototrophic bacteria are a relatively recently discovered bacterial group. Although taxonomically and phylogenetically heterogeneous, these bacteria share the following distinguishing features: the presence of bacteriochlorophyll a incorporated into reaction center and light-harvesting complexes, low levels of the photosynthetic unit in cells, an abundance of carotenoids, a strong inhibition by light of bacteriochlorophyll synthesis, and the inability to grow photosynthetically under anaerobic conditions. Aerobic anoxygenic phototrophic bacteria are classified in two marine (Erythrobacter and Roseobacter) and six freshwater (Acidiphilium, Erythromicrobium, Erythromonas, Porphyrobacter, Roseococcus, and Sandaracinobacter) genera, which phylogenetically belong to the α-1, α-3, and α-4 subclasses of the class Proteobacteria. Despite this phylogenetic information, the evolution and ancestry of their photosynthetic properties are unclear. We discuss several current proposals for the evolutionary origin of aerobic phototrophic bacteria. The closest phylogenetic relatives of aerobic phototrophic bacteria include facultatively anaerobic purple nonsulfur phototrophic bacteria. Since these two bacterial groups share many properties, yet have significant differences, we compare and contrast their physiology, with an emphasis on morphology and photosynthetic and other metabolic processes. PMID:9729607

  18. Aerobic Dance in Public Schools.

    ERIC Educational Resources Information Center

    Chiles, Barbara Ann; Moore, Suzanne

    1981-01-01

    Aerobic dance offers a challenging workout in a social atmosphere. Though some physical education instructors tend to exclude dance units from the curriculum, most could teach aerobic dance if they had a basic knowledge of aerobic routines. The outline for a unit to be used in the class is presented. (JN)

  19. Managing for Improved Aerobic Stability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aerobic deterioration or spoilage of silage is the result of aerobic microorganisms metabolizing components of the silage using oxygen. In the almost 40 years over which these silage conferences have been held, we have come to recognize the typical pattern of aerobic microbial development by which s...

  20. Modeling MTBE and BTEX in lakes and reservoirs used for recreational boating.

    PubMed

    Heald, Prescott C; Schladow, S Geoffrey; Reuter, John E; Allen, Brant C

    2005-02-15

    It is generally recognized that the bulk of fuel-related volatile organic compounds (VOCs) in lakes and reservoirs come from motorized recreational boating, but a quantitative connection between the two has been difficult to establish. A detailed boating use survey was conducted at a Northern California multiple-use lake, and the results were used to quantify daily methyl tert-butyl ether (MTBE) and benzene, toluene, ethylbenzene, and xylene (BTEX) loading from recreational boating. A one-dimensional, process-based numerical model was used to predict VOC levels as a function of the number, type, and activity of marine engines using the lake, the vertical mixing dynamics of the lake, and the volatilization rates of the individual VOCs. The model was validated on two other reservoirs to establish its applicability under a range of climatic and boating conditions. The study further confirmed the link between motorized boating and surface-water VOC contamination. In addition, the results of this study suggest that volatilization alone is inadequate to describe the loss of volatile hydrocarbons from surface waters and that some combination of additional degradation processes is involved. Under low wind conditions, these degradation processes dominate the removal of MTBE. For toluene, these processes are always more dominant than volatilization. The mean relative percent difference (RPD) between measured and simulated VOC concentrations at the study site, accounting only for volatilization losses, was 50.6% for MTBE and 113% for toluene. A first-order submodel was implemented to account for losses other than volatilization, using decay coefficients estimated from the literature. The resulting mean RPDs between measured and modeled concentrations were 14.2% for MTBE and 4.5% for toluene. PMID:15773484

  1. Mathematical models for biodegradation of chlorinated solvents. 1: Model framework

    SciTech Connect

    Zhang, X.; Banerji, S.; Bajpai, R.

    1996-12-31

    Complete mineralization of chlorinated solvents by microbial action has been demonstrated under aerobic as well as anaerobic conditions. In most of the cases, it is believed that the biodegradation is initiated by broad-specificity enzymes involved in metabolism of a primary substrate. Under aerobic conditions, some of the primary carbon and energy substrates are methane, propane, toluene, phenol, and ammonia; under anaerobic conditions, glucose, sucrose, acetate, propionate, isopropanol, methanol, and even natural organics act as the carbon source. Published biochemical studies suggest that the limiting step is often the initial part of the biodegradation pathway within the microbial system. For aerobic systems, the limiting step is thought to be the reaction catalyzed by mono- and dioxygenases which are induced by most primary substrates, although some constitutive strains have been reported. Other critical features of the biodegradative pathway include: (1) activity losses of critical enzyme(s) through the action of metabolic byproducts, (2) energetic needs of contaminant biodegradation which must be met by catabolism of the primary substrates, (3) changes in metabolic patterns in mixed cultures found in nature depending on the availability of electron acceptors, and (4) the associated accumulation and disappearance of metabolic intermediates. Often, the contaminant pool itself consists of several chlorinated solvents with separate and interactive biochemical needs. The existing models address some of the issues mentioned above. However, their ability to successfully predict biological fate of chlorinated solvents in nature is severely limited due to the existing mathematical models. Limiting step(s), inactivation of critical enzymes, recovery action, energetics, and a framework for multiple degradative pathways will be presented as a comprehensive model. 91 refs.

  2. Adsorption and biodegradation of antidiabetic pharmaceuticals in soils.

    PubMed

    Mrozik, Wojciech; Stefańska, Justyna

    2014-01-01

    Pharmaceuticals are emerging contaminants in the natural environment. Most studies of the environmental fate of these chemicals focus on their behavior in wastewater treatment processes and in sewage sludge. Little is known about their behavior in soils. In this study adsorption and biodegradation of four antidiabetic pharmaceuticals - glimepiride, glibenclamide, gliclazide and metformin - were examined in three natural soils. The sorption of sulfonylurea derivatives was high (higher than sulfonylurea herbicides for example), whereas metformin showed high mobility. Desorption rates were highest for metformin. Sorption isotherms in two of three soils fitted best to the Freundlich model. Despite their high affinity to for soil surfaces, biodegradation studies revealed that transformation of the drugs occurred. Biodegradation results were described by pseudo-first order kinetics with half-life values from 5 to over 120 d (under aerobic conditions) and indicate that none of the tested drugs can be classified as quickly biodegradable. Biodegradation under anoxic conditions was much slower; often degrading by less than 50% during time of the experiment. PMID:24083899

  3. Microbial colonization and degradation of polyethylene and biodegradable plastic bags in temperate fine-grained organic-rich marine sediments.

    PubMed

    Nauendorf, Alice; Krause, Stefan; Bigalke, Nikolaus K; Gorb, Elena V; Gorb, Stanislav N; Haeckel, Matthias; Wahl, Martin; Treude, Tina

    2016-02-15

    To date, the longevity of plastic litter at the sea floor is poorly constrained. The present study compares colonization and biodegradation of plastic bags by aerobic and anaerobic benthic microbes in temperate fine-grained organic-rich marine sediments. Samples of polyethylene and biodegradable plastic carrier bags were incubated in natural oxic and anoxic sediments from Eckernförde Bay (Western Baltic Sea) for 98 days. Analyses included (1) microbial colonization rates on the bags, (2) examination of the surface structure, wettability, and chemistry, and (3) mass loss of the samples during incubation. On average, biodegradable plastic bags were colonized five times higher by aerobic and eight times higher by anaerobic microbes than polyethylene bags. Both types of bags showed no sign of biodegradation during this study. Therefore, marine sediment in temperate coastal zones may represent a long-term sink for plastic litter and also supposedly compostable material. PMID:26790603

  4. A re-evaluation of the taste and odour of methyl tertiary butyl ether (MTBE) in drinking water.

    PubMed

    Suffet, I H

    2007-01-01

    Methyl tertiary butyl ether (MTBE) is a gasoline additive that has been found in groundwater when an underground gasoline storage tank leaks. Although dependent on the clean-up standards that are applied, clean-up costs have been estimated in the US alone to be in the billions of dollars. MTBE is considered primarily a taste and odour concern and not a toxicity issue at concentrations found in drinking water. Thus, the clean-up of MTBE problems is controlled by the MTBE odour threshold concentration (OTC). The level of clean-up and associated differential of millions of dollars is a matter of concern for water purveyors and well owners. A 1993 study of nine OTC studies showed the OTC of MTBE in water to be between 0.04 and 0.06 microg/L, a level over two orders of magnitude less than eight other studies. This 1993 study was repeated at the original laboratory in 2004 and is reported in this paper. The laboratory's quality control programme and ability to repeat one of the eight other studies indicated the laboratory was qualified to repeat its original OTC study. The flavour and odour detection threshold range in the 1993 study, however, could not be confirmed by trained assessors repeating the original study in 2004. The inconsistencies in the data and the high detection on water blanks indicate that the dilution series of the test solutions for the 1993 study were mainly at subthreshold levels. Therefore, the original study of 1993 is not a valid OTC study for MTBE and should not be used to develop drinking water and clean-up standards. The OTC of MTBE is over 15 microg/L for the eight valid studies. PMID:17489419

  5. Biodegradation of bisphenol-A in river sediment.

    PubMed

    Chang, Bea V; Yuan, Shaw Y; Chiou, Chung C

    2011-01-01

    This research investigated the aerobic and anaerobic degradation of bisphenol-A (BPA) in river sediment. With the addition of 250 μg g⁻¹ BPA, the percentages of BPA remaining in sediment from sites A, B, and C were 21.9 %, 3.5 % and 12.5 %, respectively, after 5 days of incubation under aerobic conditions; degradation was not significant after 140 days of incubation under anaerobic conditions. The aerobic degradation of BPA was enhanced by adding yeast extract (5 mg L⁻¹), sodium chloride (1 %), cellulose (0.96 mg L⁻¹), brij 30 (55 μM), brij 35 (91 μM), rhamnolipid (130 mg L⁻¹), or surfactin (43 mg L⁻¹), with rhamnolipid yielding higher BPA degradation than the other additives. 2,4-bis (1,1-dimethyl ethyl) phenol, an intermediate product resulting from the aerobic degradation of BPA was accumulated in sediments. Of the bacterial strains isolated from the sediment, strains J1, J2, J3, and J4 expressed the best aerobic degrading ability. The highest BPA degradation rate was found in the sediment by the addition of strains J1, J2, J3, and J4 combined, whereas the sediment without the addition of the 4 strains had the lowest biodegradation rate. This research offers feasible methods for the removal of BPA in river sediment for bioremediation. PMID:21714622

  6. [Methyl tert-butyl ether (MTBE) in atmosphere of the Pearl River Delta, China].

    PubMed

    Wang, Bo-guang; Shao, Min; Zhang, Yuan-hang; Lü, Wan-Ming; Zhou, Yan

    2007-07-01

    The concentration of methyl tert-butyl ether (MTBE) and its spatio-temporal distribution were researched in atmosphere of the Pearl River Delta (PRD) by sampling with air sampling canisters and analyzing with pre-concentrator and gas chromatograph-mass spectrum instrument. The results showed that 1) MTBE could be prevalently checked in atmosphere of traffic area, industrial area, residential area and commercial area of the PRD, and its range of hourly average concentration in the long-term observation was from 0 - 1.250 microg m(-3), the summer had more serious pollution than the spring, and urban was the central area of high MTBE concentration, and suburban in the downwind was obviously polluted by the urban air. 2) During the enhanced observation in summertime, the diurnal average concentration of Guangzhou urban site was (1.520 +/- 0.370) microg m(-3), which was about 7 times of Huadou site in the downwind of Guangzhou and over 100 times of Conghua site in the background of Guangzhou. In urban, 2 peak values appeared in the period of 10:00 - 12:00 and 16:00 - 18:00 respectively, and the nighttime had the lowest average concentration, but the suburban in the downwind had the peak value in the nighttime. 3) During the enhanced observation in wintertime, the diurnal average concentration of Guangzhou urban site was (0.950 +/- 0.240) microg m(-3), which was 3.6 times of Xinken site in the downwind of Guangzhou. Several peak values appeared on the diurnal variation, the high concentration period of urban was in 18:00 - 22:00, and that of suburban was in 04:00 - 10:00 of the next day. 4) When it was weak sunshine, the concentration of MTBE beside the urban traffic roadside was decreasing with the height increasing, but when it was strong sunshine, it was increasing with the height increasing. So, except the original emission from the automobiles, MTBE still had the secondary pollution sources formed by air photochemical reaction. PMID:17891978

  7. Biodegradation of free cyanide and subsequent utilisation of biodegradation by-products by Bacillus consortia: optimisation using response surface methodology.

    PubMed

    Mekuto, Lukhanyo; Ntwampe, Seteno Karabo Obed; Jackson, Vanessa Angela

    2015-07-01

    A mesophilic alkali-tolerant bacterial consortium belonging to the Bacillus genus was evaluated for its ability to biodegrade high free cyanide (CN(-)) concentration (up to 500 mg CN(-)/L), subsequent to the oxidation of the formed ammonium and nitrates in a continuous bioreactor system solely supplemented with whey waste. Furthermore, an optimisation study for successful cyanide biodegradation by this consortium was evaluated in batch bioreactors (BBs) using response surface methodology (RSM). The input variables, that is, pH, temperature and whey-waste concentration, were optimised using a numerical optimisation technique where the optimum conditions were found to be as follows: pH 9.88, temperature 33.60 °C and whey-waste concentration of 14.27 g/L, under which 206.53 mg CN(-)/L in 96 h can be biodegraded by the microbial species from an initial cyanide concentration of 500 mg CN(-)/L. Furthermore, using the optimised data, cyanide biodegradation in a continuous mode was evaluated in a dual-stage packed-bed bioreactor (PBB) connected in series to a pneumatic bioreactor system (PBS) used for simultaneous nitrification, including aerobic denitrification. The whey-supported Bacillus sp. culture was not inhibited by the free cyanide concentration of up to 500 mg CN(-)/L, with an overall degradation efficiency of ≥ 99 % with subsequent nitrification and aerobic denitrification of the formed ammonium and nitrates over a period of 80 days. This is the first study to report free cyanide biodegradation at concentrations of up to 500 mg CN(-)/L in a continuous system using whey waste as a microbial feedstock. The results showed that the process has the potential for the bioremediation of cyanide-containing wastewaters. PMID:25721526

  8. Occurrence and fate modeling of MTBE and BTEX compounds in a Swiss Lake used as drinking water supply.

    PubMed

    Schmidt, Torsten C; Haderlein, Stefan B; Pfister, Rolf; Forster, Richard

    2004-03-01

    Emissions of fuel components from boating use on multiple-use lakes and reservoirs are of high concern with regard to the drinking water supply from such water bodies. We report results of a detailed study on the occurrence, sources and fate of aromatic hydrocarbons and methyl tert-butyl ether (MTBE) in a typical holomictic lake, Lake Zurich, that supplies drinking water for the largest Swiss city. Emphasis of the investigation was on the fuel oxygenate MTBE, which was found in concentrations up to 1.4 microg/L in the epilimnion and up to 0.05microg/L in the hypolimnion of the lake. The concentration difference was due to the stratification of the lake during the boating season with very limited water exchange across the thermocline. MTBE and BTEX nearly completely volatilized before vertical lake mixing occurred in winter. Spatial and temporal variations of MTBE concentrations in the lake were observed and successfully predicted using two complementary box models (MASAS Light and Aquasim). The drinking water supply from holomictic lakes is not at risk for the scenarios studied if water is extracted from well below the thermocline. Since emissions of unburned gasoline into such water bodies are caused predominantly by boating activities, restrictions of highly emitting two-stroke engines could substantially reduce the MTBE and BTEX load of the epilimnion during the boating season. PMID:15016529

  9. Characterization of biodegradation intermediates of nonionic surfactants by MALDI-MS. 2. Oxidative biodegradation profiles of uniform octylphenol polyethoxylate in 18O-labeled water.

    PubMed

    Sato, Hiroaki; Shibata, Atsushi; Wang, Yang; Yoshikawa, Hiromichi; Tamura, Hiroto

    2003-01-01

    This paper reports the characterization of the biodegradation intermediates of octylphenol octaethoxylate (OP(8)EO) by means of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The biodegradation test study was carried out in a pure culture (Pseudomonas putida S-5) under aerobic conditions using OP(8)EO as the sole carbon source and (18)O-labeled water as an incubation medium. In the MALDI-MS spectra of biodegraded samples, a series of OP(n)EO molecules with n = 2-8 EO units and their corresponding carboxylic acid products (OP(n)EC) were observed. The use of purified OP(8)EO enabled one to distinguish the shortened OPEO molecules as biodegradation intermediates. Furthermore, the formation of OP(8)EC (the oxidized product of OP(8)EO) supported the notion that terminal oxidation is a step in the biodegradation process. When biodegradation study was carried out in (18)O-labeled water, incorporation of (18)O atoms into the carboxyl group was observed for OPEC, while no incorporation was observed for the shortened OPEO products. These results could provide some rationale to the biodegradation mechanism of alkylphenol polyethoxylates. PMID:12523845

  10. Occurrence and Biodegradation of Nonylphenol in the Environment

    PubMed Central

    Mao, Zhen; Zheng, Xiao-Fei; Zhang, Yan-Qiu; Tao, Xiu-Xiang; Li, Yan; Wang, Wei

    2012-01-01

    Nonylphenol (NP) is an ultimate degradation product of nonylphenol polyethoxylates (NPE) that is primarily used in cleaning and industrial processes. Its widespread use has led to the wide existence of NP in various environmental matrices, such as water, sediment, air and soil. NP can be decreased by biodegradation through the action of microorganisms under aerobic or anaerobic conditions. Half-lives of biodegradation ranged from a few days to almost one hundred days. The degradation rate for NP was influenced by temperature, pH and additions of yeast extracts, surfactants, aluminum sulfate, acetate, pyruvate, lactate, manganese dioxide, ferric chloride, sodium chloride, hydrogen peroxide, heavy metals, and phthalic acid esters. Although NP is present at low concentrations in the environment, as an endocrine disruptor the risks of long-term exposure to low concentrations remain largely unknown. This paper reviews the occurrence of NP in the environment and its aerobic and anaerobic biodegradation in natural environments and sewage treatment plants, which is essential for assessing the potential risk associated with low level exposure to NP and other endocrine disruptors. PMID:22312266

  11. EVALUATION OF A PILOT-SCALE ULTRAVIOLET (UV) LIGHT AND OZONE TREATMENT SYSTEM FOR REMOVAL OF MTBE FROM DRINKING WATER SOURCES

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) is currently evaluating package plant advanced oxidation process (AOP) systems to treat methyl tertiary butyl ether (MTBE) in drinking water supplies (e.g., surface water, groundwater). MTBE has been identified as a potential carcin...

  12. Concentrations and potential health risks of methyl tertiary-butyl ether (MTBE) in air and drinking water from Nanning, South China.

    PubMed

    Zhang, Li'e; Qin, Jian; Zhang, Zhiyong; Li, Qin; Huang, Jiongli; Peng, Xiaowu; Qing, Li; Liang, Guiqiang; Liang, Linhan; Huang, Yuman; Yang, Xiaobo; Zou, Yunfeng

    2016-01-15

    Levels of methyl tertiary-butyl ether (MTBE) in occupational air, ambient air, and drinking water in Nanning, South China, were investigated, and then their potential health risks to occupational workers and the general public were evaluated. Results show that the MTBE concentration in occupational air from 13 service stations was significantly higher than that in ambient air from residential areas (p<0.0001); both are far lower than the threshold limit value-time weighted average of MTBE regulated in the United States (US). The drinking water samples from household taps yielded detectable MTBE in the range of 0.04-0.33 μg/L, which is below the US drinking water standard of 20-40 μg/L. The non-carcinogenic risk of MTBE from air inhalation may be negligible because the calculated hazard quotient was less than 1. The mean MTBE lifetime cancer risk was within the acceptable limit of 1 × 10(-6) to 1 × 10(-4), but the lifetime cancer risk of refueling workers in the urban service station at the 95th percentile slightly exceeded the maximum acceptable carcinogen risk (1 × 10(-4)), indicating the potential carcinogenic health effects on the population highly exposed to MTBE in this region. The hazard index and carcinogenic risk of MTBE in drinking water were significantly lower than the safe limit of US Environmental Protection Agency, suggesting that drinking water unlikely poses significant health risks to the residents in Nanning. PMID:26479908

  13. IN SITU BIOREMEDIATION OF SOILS, SEDIMENTS AND WATERS CONTAMINATED WITH MTBE AND BTEX BY USING SOLID OXYGEN SOURCE, ISOLITE B, AND THE BACTERIUM PM1

    EPA Science Inventory

    BTEX (benzene, toluene, ethylbenzene, xylenes) and MTBE are present in soils at many American crossroads. The objective of this controlled study was to determine if biologically active in situ BioNets could bioremediate MTBE and BTEX contaminated groundwater. Seven BioNets, mos...

  14. TREATMENT OF MTBE - CONTAMINATED WATER USING THE FENTON'S REAGENT: EFFECTS OF SINGLE AND MULTIPLE ADDITION OF REAGENT ON THE OVERALL REACTION EFFICIENCY

    EPA Science Inventory

    In 1997 EPA issued a "Drinking Water Advisory" for MTBE recommending concentration limits of 20-40 ug/L to avoid taste and odor problems. Further regulations classified MTBE in the list of "potential human carcinogens" in 2000. Therefore, intensive research efforts are currently ...

  15. STUDIES ON THE REMEDIATION OF MTBE - CONTAMINATED WATER USING THE FENTON'S REAGENT: THE EFFECT OF MODIFIED FERROUS IRON/HYDROGEN PEROXIDE RATIOS

    EPA Science Inventory

    Methyl tert-butyl ether (MTBE) was initially used as an octane enhancer, and more recently as an oxygenate in reformulated gasoline. Despite its beneficial effect for air quality improvement, MTBE has recently been considered a threat to water quality since its detection in groun...

  16. Methyl tert-butyl ether degradation in the unsaturated zone and the relation between MTBE in the atmosphere and shallow groundwater

    USGS Publications Warehouse

    Baehr, A.L.; Charles, E.G.; Baker, R.J.

    2001-01-01

    Atmospheric methyl tert-butyl ether (MTBE) concentrations in southern New Jersey generally exceeded concentrations in samples taken from the unsaturated zone. A simple unsaturated zone transport model indicates that MTBE degradation can explain the attenuation with half-lives from a few months to a couple of years. Tert-butyl alcohol (TBA), a possible degradation product of MTBE, was detected in unsaturated-zone samples at concentrations exceeding atmospheric levels at some sites, suggesting the possible conversion of MTBE to TBA. At sites where MTBE was detected in shallow groundwater, the concentration was typically higher than the overlying unsaturated-zone concentration. This observation is consistent with outgassing from the aquifer and combined with the unsaturated-zone attenuation suggests some of the MTBE detections in shallow groundwater are nonatmospheric in origin, coming from leaking tanks, road runoff, or other sources. The identification of sources of MTBE in groundwater and attenuation mechanisms through the hydrologic cycle is critical in developing an understanding of the long-term effect of MTBE releases.

  17. Editorial: Biodegradable Materials

    PubMed Central

    Schaschke, Carl; Audic, Jean-Luc

    2014-01-01

    This Special Issue “Biodegradable Materials” features research and review papers concerning recent advances on the development, synthesis, testing and characterisation of biomaterials. These biomaterials, derived from natural and renewable sources, offer a potential alternative to existing non-biodegradable materials with application to the food and biomedical industries amongst many others. In this Special Issue, the work is expanded to include the combined use of fillers that can enhance the properties of biomaterials prepared as films. The future application of these biomaterials could have an impact not only at the economic level, but also for the improvement of the environment. PMID:25421242

  18. Cloning and expression of vgb gene in Bacillus cereus, improve phenol and p-nitrophenol biodegradation

    NASA Astrophysics Data System (ADS)

    Vélez-Lee, Angel Eduardo; Cordova-Lozano, Felipe; Bandala, Erick R.; Sanchez-Salas, Jose Luis

    2016-02-01

    In this work, the vgb gene from Vitrocilla stercoraria was used to genetically modify a Bacillus cereus strain isolated from pulp and paper wastewater effluent. The gene was cloned in a multicopy plasmid (pUB110) or uni-copy gene using a chromosome integrative vector (pTrpBG1). B. cereus and its recombinant strains were used for phenol and p-nitrophenol biodegradation using aerobic or micro-aerobic conditions and two different temperatures (i.e. 37 and 25 °C). Complete (100%) phenol degradation was obtained for the strain where the multicopy of vgb gene was present, 98% for the strain where uni-copy gene was present and 45% for wild type strain for the same experimental conditions (i.e. 37 °C and aerobic condition). For p-nitrophenol degradation at the same conditions, the strain with the multi-copy vgb gene was capable to achieve 50% of biodegradation, ∼100% biodegradation was obtained using the uni-copy strain and ∼24% for wild type strain. When the micro-aerobic condition was tested, the biodegradation yield showed a significant decreased. The biodegradation trend observed for aerobic was similar for micro-aerobic assessments: the modified strains showed higher degradation rates when compared with wild type strain. For all experimental conditions, the highest p-nitrophenol degradation was observed using the strain with uni-copy of vgb gene. Besides the increase of biodegradative capability of the strain, insertion of the vgb gene was observed able to modify other morphological characteristics such as avoiding the typical flake formation in the B. cereus culture. In both cases, the modification seems to be related with the enhancement of oxygen supply to the cells generated by the vgb gene insertion. The application of the genetically modified microorganism (GMM) to the biodegradation of pollutants in contaminated water possesses high potential as an environmentally friendly technology to facing this emergent problem.

  19. Biodegradation of cresol isomers in anoxic aquifers.

    PubMed Central

    Smolenski, W J; Suflita, J M

    1987-01-01

    The biodegradation of o-, m-, and p-cresol was examined in material obtained from a shallow anaerobic alluvial sand aquifer. The cresol isomers were preferentially metabolized, with p-cresol being the most easily degraded. m-Cresol was more persistent than the para-isomer, and o-cresol persisted for over 90 days. Biodegradation of cresol isomers was favored under sulfate-reducing conditions (SRC) compared with that under methanogenic conditions (MC). Slurries that were acclimated to p-cresol metabolism transformed this substrate at 18 and 330 nmol/h per g (dry weight) for MC and SRC, respectively. Inhibition of electron flow to sulfate reduction with 2.0 mM molybdate reduced p-cresol metabolism in incubations containing sulfate. When methanogenesis was blocked with 5 mM bromoethanesulfonic acid in incubations lacking sulfate, p-cresol catabolism was retarded. Under SRC 3.4 mol of sulfate was consumed per mol of p-cresol metabolized. The addition of sulfate to methanogenic incubations stimulated p-cresol degradation. Simultaneous adaptation studies in combination with spectrophotometric and chromatographic analysis of metabolites indicated that p-cresol was oxidized under SRC to p-hydroxybenzoate via the corresponding alcohol and aldehyde. This series of reactions was inhibited under sulfate-limited or aerobic conditions. Therefore, the primary catabolic event for p-cresol decomposition under SRC appears to involve the hydroxylation of the aryl methyl group. PMID:3579279

  20. Biodegradation of glycol ethers in soil

    SciTech Connect

    Gonsior, S.J.; West, R.J.

    1995-08-01

    Because of the widespread use of glycol ethers in applications ranging from consumer products to use as chemical intermediates, there is a need to better understand the fate of these compounds in the environment. Soil biodegradation studies were conducted for three propylene glycol ethers: 1-methoxy-2-propanol, 1-phenoxy-2-propanol, and 1-methoxy-2-propanol acetate. The test compounds were labeled with carbon-14 at either the methoxy or phenoxy substituents. Biodegradation of the three compounds was observed in two sandy loam soils. The time required for disappearance of 50% of the test compounds ranged from < 1 d at 0.2 ppm (w/w) to <7 d at 107 ppm. Degradation rates were slower in a sandy soil, reflecting the lower concentration of microorganisms present. No significant accumulation of intermediate products was observed, and ultimate yields of {sup 14}CO{sub 2} were in the range of 40 to 65% of the initial concentration. Results indicated that the glycol ethers were degraded in a variety of soils under aerobic conditions.

  1. Assessing the fate of biodegradable volatile organic contaminants in unsaturated soil filter systems

    NASA Astrophysics Data System (ADS)

    Thullner, Martin; de Biase, Cecilia; Hanzel, Joanna; Reger, Daniel; Wick, Lukas; Oswald, Sascha; van Afferden, Manfred; Schmidt, Axel; Reiche, Nils; Jechalke, Sven

    2010-05-01

    The assessment of contaminant biodegradation in the subsurface is challenged by various abiotic processes leading to a reduction of contaminant concentration without a destructive mass removal of the contaminant. In unsaturated porous media, this interplay of processes is further complicated by volatilization. Many organic contaminants are sufficiently volatile to allow for significant fluxes from the water phase into the soil air, which can eventually lead to an emission of contaminants into the atmosphere. Knowledge of the magnitude of these emissions is thus required to evaluate the efficiency of bioremediation in such porous media and to estimate potential risks due to these emissions. In the present study, vertical flow constructed wetlands were investigated at the pilot scale as part of the SAFIRA II project. The investigated wetland system is intermittently irrigated by contaminated groundwater containing the volatile compounds benzene and MTBE. Measured concentration at the in- and outflow of the system demonstrate a high mass removal rate, but the highly transient flow and transport processes in the system challenge the quantification of biodegradation and volatilization and their contribution to the observed mass removal. By a combination of conservative solute tracer tests, stable isotope fractionation and measurements of natural radon concentration is the treated groundwater is was possible to determine the contribution of biodegradation and volatilization to total mass removal. The results suggest that for the investigated volatile compounds biodegradation is the dominating mass removal process with volatilization contributing only to minor or negligible amounts. These results can be confirmed by reactive transport simulations and were further supported by laboratory studies showing that also gas phase gradients of volatile compounds can be affected by biodegradation suggesting the unsaturated zone to act as a biofilter for contaminants in the soil air.

  2. A comparative study of biodiesel production using methanol, ethanol, and tert-butyl methyl ether (MTBE) under supercritical conditions.

    PubMed

    Farobie, Obie; Matsumura, Yukihiko

    2015-09-01

    In this study, biodiesel production under supercritical conditions among methanol, ethanol, and tert-butyl methyl ether (MTBE) was compared in order to elucidate the differences in their reaction behavior. A continuous reactor was employed, and experiments were conducted at various reaction temperatures (270-400 °C) and reaction times (3-30 min) and at a fixed pressure of 20 MPa and an oil-to-reactant molar ratio of 1:40. The results showed that under the same reaction conditions, the supercritical methanol method provided the highest yield of biodiesel. At 350 °C and 20 MPa, canola oil was completely converted to biodiesel after 10, 30, and 30 min in the case of - supercritical methanol, ethanol, and MTBE, respectively. The reaction kinetics of biodiesel production was also compared for supercritical methanol, ethanol, and MTBE. PMID:26004381

  3. Morphological and biodegradability studies of Euphorbia latex modified polyester - Banana fiber composites

    NASA Astrophysics Data System (ADS)

    Rai, Bhuvneshwar; Kumar, Gulshan; Diwan, R. K.

    2016-05-01

    The composites of Banana fiber were prepared using polyester resin blended Euphorbia coagulum, morphology and the degree of rate of aerobic biodegradation of the prepared composites were studied. Polyester resin blended Euphorbia coagulum containing Banana fiber, Euphorbia coagulum and polyester resin taken in the ratio 40: 24: 36 was used for the study, which was the optimum composition of the composite reported in a previous study by the authors. In the biodegradability study cellulose has been used as positive reference material. Result shows that Euphorbia coagulum modified polyester - Banana fiber composites exhibited biodegradation to the extent of around 40%. The use of developed green composites may help in reducing the generation of non-biodegradable polymeric wastes.

  4. Microbial degradation of 4-monobrominated diphenyl ether in an aerobic sludge and the DGGE analysis of diversity.

    PubMed

    Chen, Chun-Yao; Wang, Chun-Kang; Shih, Yang-Hsin

    2010-07-01

    Polybrominated diphenyl ethers (PBDEs) were applied as flame retardant additives in polymers for many plastic and electronic products. Due to their ubiquitous distribution in the environment, potential toxicity to human and tendency for bioaccumulation, PBDEs have raised public safety concern. In this study we examined the degradation of 4-monobrominated diphenyl ether (4-BDE) in aerobic sludge, as a model for PBDE biodegradation. Degradation of 4-BDE was observed in aerobic sludge. Co-metabolism with toluene or diphenyl ether facilitated 4-BDE biodegradation in terms of kinetics and efficiency. Diphenyl ether seems to perform slightly better as an auxiliary carbon source than toluene in facilitating 4-BDE degradation. During the experiment we identified diphenyl ether by gas chromatography/mass spectrometry(GC/MS), which indicates that an anaerobic debromination has occurred. Bacterial community composition was monitored with denaturing gradient gel electrophoresis. The fragments enriched in 4-BDE-degrading aerobic sludge samples belong to presumably a novel anaerobic Clostridiales species distantly related to all known debrominating microbes. This suggests that 4-BDE biodegradation can occur in anaerobic micro-niche in an apparently aerobic environment, by a previously unknown bacterial species. These findings can provide better understandings of biodegradation of brominated diphenyl ethers and can facilitate the prediction of the fate of PBDEs in the environment. PMID:20512728

  5. Biodegradable Materials for Nonwovens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Demand for nonwovens is increasing globally, particularly in the disposable products area. As the consumption of nonwoven products with short life increases, the burden on waste disposal also rises. In this context, biodegradable nonwovens become more important today and for the future. Several new ...

  6. Aerobic treatability of waste effluent from the leather finishing industry. Master's thesis

    SciTech Connect

    Vinger, J.A.

    1993-12-01

    The Seton Company supplies finished leather products exclusively for the automotive industry. In the process of finishing leather, two types of wastewaters are generated. The majority of the wastewater is composed of water-based paint residuals while the remainder is composed of solvent-based coating residuals. Aerobic treatability studies were conducted using water-based and solvent-based waste recirculatory waters from the Seton Company's Saxton, Pennsylvania processing plant. The specific objective was to determine the potential for using aerobic biological processes to biodegrade the industry's wastes and determine the potential for joint treatment at the local publicly owned treatment works (POTW). This study was accomplished in two phases. Phase I was conducted during the Spring Semester 1993 and consisted of aerobic respirometer tests of the raw wastes and mass balance analysis. The results of Phase I were published in a report to the Seton Company as Environmental Resources Research Institute project number 92C.II40R-1. Phase II was conducted during the Summer Semester 1993 and consisted of bench-scale reactor tests and additional aerobic respirometer tests. The aerobic respirometer batch tests and bench-scale reactor tests were used to assess the treatability of solvent-based and water-based wastewaters and determine the degree of biodegradability of the wastewaters. Mass balance calculations were made using measured characteristics.

  7. Effect and behaviour of different substrates in relation to the formation of aerobic granular sludge.

    PubMed

    Pronk, M; Abbas, B; Al-Zuhairy, S H K; Kraan, R; Kleerebezem, R; van Loosdrecht, M C M

    2015-06-01

    When aerobic granular sludge is applied for industrial wastewater treatment, different soluble substrates can be present. For stable granular sludge formation on volatile fatty acids (e.g. acetate), production of storage polymers under anaerobic feeding conditions has been shown to be important. This prevents direct aerobic growth on readily available chemical oxygen demand (COD), which is thought to result in unstable granule formation. Here, we investigate the impact of acetate, methanol, butanol, propanol, propionaldehyde, and valeraldehyde on granular sludge formation at 35 °C. Methanogenic archaea, growing on methanol, were present in the aerobic granular sludge system. Methanol was completely converted to methane and carbon dioxide by the methanogenic archaeum Methanomethylovorans uponensis during the 1-h anaerobic feeding period, despite the relative high dissolved oxygen concentration (3.5 mg O2 L(-1)) during the subsequent 2-h aeration period. Propionaldehyde and valeraldehyde were fully disproportionated anaerobically into their corresponding carboxylic acids and alcohols. The organic acids produced were converted to storage polymers, while the alcohols (produced and from influent) were absorbed onto the granular sludge matrix and converted aerobically. Our observations show that easy biodegradable substrates not converted anaerobically into storage polymers could lead to unstable granular sludge formation. However, when the easy biodegradable COD is absorbed in the granules and/or when the substrate is converted by relatively slow growing bacteria in the aerobic period, stable granulation can occur. PMID:25616527

  8. Influence of an aniline supplement on the stability of aerobic granular sludge.

    PubMed

    Dai, Yajie; Jiang, Yixin; Su, Haijia

    2015-10-01

    In order to evaluate the stability of aerobic granules in a toxic environment, this study discussed the influence of an aniline supplement on the properties and microbial community of aerobic granules. In the early stages of sequencing batch reactor (SBR) operation, an aniline supplement slightly affected the properties of the aerobic granules (strength, growth rate, SVI and so on). This effect was thereafter removed because of a change in the microbial community and the structure of aerobic granules: with the present of aniline, microbes with biodegradation ability appeared and gathered in the aerobic granules and the aerobic granules densified and settled faster as their SVI decreased to 35 mL/g and settling velocity increased to 41.56 m/h. When a synthetic waste water containing acetate as carbon source was used as influent, aniline (10-500 mg/L) could be degraded in 6 h, at a rate as high as 37.5 mg aniline/(L·h), with a removal rate in excess of 90%, while the effluent COD fell below 100 mg/L from the initial about 2000 mg/L. The aerobic granules cultured by acetate were compact, stable and resistant to aniline. PMID:26233584

  9. Aerobic landfill bioreactor

    DOEpatents

    Hudgins, Mark P; Bessette, Bernard J; March, John C; McComb, Scott T.

    2002-01-01

    The present invention includes a system of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120.degree. F. and 140.degree. F. in steady state.

  10. Aerobic landfill bioreactor

    DOEpatents

    Hudgins, Mark P; Bessette, Bernard J; March, John; McComb, Scott T.

    2000-01-01

    The present invention includes a method of decomposing municipal solid waste (MSW) within a landfill by converting the landfill to aerobic degradation in the following manner: (1) injecting air via the landfill leachate collection system (2) injecting air via vertical air injection wells installed within the waste mass; (3) applying leachate to the waste mass using a pressurized drip irrigation system; (4) allowing landfill gases to vent; and (5) adjusting air injection and recirculated leachate to achieve a 40% to 60% moisture level and a temperature between 120.degree. F. and 140.degree. F. in steady state.

  11. Multiphase Modeling of Flow, Transport, and Biodegradation in a Mesoscale Landfill Bioreactor

    SciTech Connect

    Oldenburg, Curtis M.; Borglin, Sharon E.; Hazen, Terry C.

    2002-02-01

    The need to control gas and leachate production and minimize refuse volume in municipal solid waste landfills has motivated the development of landfill simulation models to predict and design optimal treatment processes. We have developed a multiphase and multicomponent nonisothermal module called T2LBM for the three-dimensional TOUGH2 flow and transport simulator. T2LBM can be used to simulate aerobic or anaerobic biodegradation of municipal solid waste and the associated flow and transport of gas and liquid through the refuse mass. Acetic acid is used as a proxy for all biodegradable substrates in the refuse. T2LBM incorporates a Monod kinetic rate law for the biodegradation of acetic acid by either aerobic or anaerobic microbes as controlled by the local oxygen concentration. We have verified the model against published data, and applied it to our own mesoscale laboratory aerobic landfill bioreactor experiments. We observe spatial variability of flow and biodegradation consistent with permeability heterogeneity and the geometry of the radial grid. The model is capable of matching results of a shut-in test where the respiration of the system is measured over time.

  12. Anaerobic Biodegradation of Pristane by Nitrate Reducing Bacteria

    NASA Astrophysics Data System (ADS)

    Dawson, K. S.; Freeman, K. H.; Macalady, J. L.

    2007-12-01

    In recent sediments, microbial biodegradation provides a control on the long-term preservation of organic matter, through the preferential loss of certain biomolecules and the alteration and concentration of other more recalcitrant molecules. Biodegradation of hydrocarbons derived from membrane lipids, has been demonstrated by both aerobic and strictly anaerobic culturing experiments. The isoprenoid pristane, once considered stable under anaerobic conditions, is in fact degraded by a denitrifying microcosm (BREGNARD et al., 1997) and a methanogenic, sulphate-reducing enrichment culture (GROSSI, 2000). We recently demonstrated pristane biodegradation and accompanying loss of nitrate by an activated sludge isolate. The measured nitrate consumption accounts for a 7.1 +/- 0.4 mg loss of pristane, 4.74% of the initial substrate, in 181 days, assuming pristane conversion to CO2. We have characterized the microorganisms active in the biodegradation process, through the creation of a 16S rDNA clone library, as well as fluorescence in situ hybridization (FISH). Experiments are in progress to enrich cultures of sulfate reducing bacteria that utilize pristane as a sole carbon source and to characterize reaction mechanisms in pristane-oxidizing pathways.

  13. Biodegradation of oil refinery wastes under OPA and CERCLA

    SciTech Connect

    Gamblin, W.W.; Banipal, B.S.; Myers, J.M.

    1995-12-31

    Land treatment of oil refinery wastes has been used as a disposal method for decades. More recently, numerous laboratory studies have been performed attempting to quantify degradation rates of more toxic polycyclic aromatic hydrocarbon compounds (PAHs). This paper discusses the results of the fullscale aerobic biodegradation operations using land treatment at the Macmillan Ring-Free Oil refining facility. The tiered feasibility approach of evaluating biodegradation as a treatment method to achieve site-specific cleanup criteria, including pilot biodegradation operations, is discussed in an earlier paper. Analytical results of biodegradation indicate that degradation rates observed in the laboratory can be met and exceeded under field conditions and that site-specific cleanup criteria can be attained within a proposed project time. Also prevented are degradation rates and half-lives for PAHs for which cleanup criteria have been established. PAH degradation rates and half-life values are determined and compared with the laboratory degradation rates and half-life values which used similar oil refinery wastes by other in investigators (API 1987).

  14. Biodegradability of activated sludge organics under anaerobic conditions.

    PubMed

    Ekama, G A; Sötemann, S W; Wentzel, M C

    2007-01-01

    From an experimental and theoretical investigation of the continuity of activated sludge organic (COD) compounds along the link between the fully aerobic or N removal activated sludge and anaerobic digestion unit operations, it was found that the unbiodegradable particulate organics (i) originating from the influent wastewater and (ii) generated by the activated sludge endogenous process, as determined from response of the activated sludge system, are also unbiodegradable under anaerobic digestion conditions. This means that the activated sludge biodegradable organics that can be anaerobically digested can be calculated from the active fraction of the waste activated sludge based on the widely accepted ordinary heterotrophic organism (OHO) endogenous respiration/death regeneration rates and unbiodegradable fraction. This research shows that the mass balances based steady state and dynamic simulation activated sludge, aerobic digestion and anaerobic digestion models provide internally consistent and externally compatible elements that can be coupled to produce plant wide steady state and dynamic simulation WWTP models. PMID:17045327

  15. Anaerobic Biodegradation of Ethylene Glycol within Hydraulic Fracturing Fluid

    NASA Astrophysics Data System (ADS)

    Heyob, K. M.; Mouser, P. J.

    2014-12-01

    Ethylene glycol (EG) is a commonly used organic additive in hydraulic fracturing fluids used for shale gas recovery. Under aerobic conditions, this compound readily biodegrades to acetate and CO2 or is oxidized through the glycerate pathway. In the absence of oxygen, organisms within genera Desulfovibrio, Acetobacterium, and others can transform EG to acetaldehyde, a flammable and suspected carcinogenic compound. Acetaldehyde can then be enzymatically degraded to ethanol or acetate and CO2. However, little is known on how EG degrades in the presence of other organic additives, particularly under anaerobic conditions representative of deep groundwater aquifers. To better understand the fate and attenuation of glycols within hydraulic fracturing fluids we are assessing their biodegradation potential and pathways in batch anaerobic microcosm treatments. Crushed Berea sandstone was inoculated with groundwater and incubated with either EG or a synthetic fracturing fluid (SFF) containing EG formulations. We tracked changes in dissolved organic carbon (DOC), EG, and its transformation products over several months. Approximately 41% of bulk DOC in SFF is degraded within 21 days, with 58% DOC still remaining after 63 days. By comparison, this same SFF degrades by 70% within 25 days when inoculated with sediment-groundwater microbial communities, suggesting that bulk DOC degradation occurs at a slower rate and to a lesser extent with bedrock. Aerobic biodegradation of EG occurs rapidly (3-7 days); however anaerobic degradation of EG is much slower, requiring several weeks for substantial DOC loss to be observed. Ongoing experiments are tracking the degradation pathways of EG alone and in the presence of SFF, with preliminary data showing incomplete glycol transformation within the complex hydraulic fracturing fluid mixture. This research will help to elucidate rates, processes, and pathways for EG biodegradation and identify key microbial taxa involved in its degradation.

  16. Aerobic Fitness and School Children.

    ERIC Educational Resources Information Center

    Hinkle, J. Scott

    1997-01-01

    Provides school counselors with information on aerobic exercise (specifically running) and the psychological, behavioral, and physical benefits children obtained by participating in fitness programs. Recommends collaboration between school counselors and physical education teachers and gives a preliminary discussion of aerobic running and its…

  17. Aerobic Fitness and School Children.

    ERIC Educational Resources Information Center

    Hinkle, J. Scott

    1992-01-01

    Provides school counselors with information regarding aerobic exercise (specifically running), and the psychological, behavioral, and physical benefits children obtain by participating in fitness programs. Presents methods of collaboration between school counselors and physical education teachers. Offers preliminary discussion of aerobic running…

  18. Exercise, Animal Aerobics, and Interpretation?

    ERIC Educational Resources Information Center

    Oliver, Valerie

    1996-01-01

    Describes an aerobic activity set to music for children that mimics animal movements. Example exercises include walking like a penguin or jumping like a cricket. Stresses basic aerobic principles and designing the program at the level of children's motor skills. Benefits include reaching people who normally don't visit nature centers, and bridging…

  19. Safe biodegradable fluorescent particles

    DOEpatents

    Martin, Sue I.; Fergenson, David P.; Srivastava, Abneesh; Bogan, Michael J.; Riot, Vincent J.; Frank, Matthias

    2010-08-24

    A human-safe fluorescence particle that can be used for fluorescence detection instruments or act as a safe simulant for mimicking the fluorescence properties of microorganisms. The particle comprises a non-biological carrier and natural fluorophores encapsulated in the non-biological carrier. By doping biodegradable-polymer drug delivery microspheres with natural or synthetic fluorophores, the desired fluorescence can be attained or biological organisms can be simulated without the associated risks and logistical difficulties of live microorganisms.

  20. Rapid identification of microorganisms for biodegradation of alkylphenols and alkylphenol ethercarboxylates

    SciTech Connect

    Hemming, B.; Williams, J.B.

    1995-12-31

    Alkylphenols, especially nonylphenol and octylphenol, are used in a wide variety of applications. These compounds, and alkylphenol ethercarboxylates, are also believed to be formed during the biodegradation of alkylphenol ethoxylates in activated sludge wastewater treatment systems. Microbe Inotech Laboratories has developed a rapid assay to identify the microorganisms present in activated sludge wastewater treatment systems (GC-FAME) and a screening assay to measure the biodegradation of compounds. These assays were used to show that alkylphenols and their corresponding ethercarboxylates were degraded aerobically even when these compounds were the sole carbon source.

  1. Toxicity of methyl tertiary-butyl ether (MTBE) following exposure of Wistar Rats for 13 weeks or one year via drinking water.

    PubMed

    Bermudez, Edilberto; Willson, Gabrielle; Parkinson, Horace; Dodd, Darol

    2012-09-01

    Thirteen-week and one-year toxicity studies of methyl tertiary-butyl ether (MTBE) administered in drinking water to Wistar rats were conducted. Male and female rats were exposed to MTBE in drinking water at 0.5, 3, 7.5 and 15 mg ml(-1) for 13 weeks and at 0.5, 3 and 7.5 (males) or 0.5, 3 and 15 mg ml(-1) (females) for 1 year. Body weights were reduced only in males following 13 weeks of exposure. Reduced water consumption and urine output were observed in males and females exposed to MTBE. Kidney cell replication and α(2u)-globulin levels in males were increased at 1 and 4 weeks of MTBE exposure and tubular cell regeneration was increased in male kidneys exposed to MTBE concentrations of 7.5 mg ml(-1) or greater for 13 weeks. Wet weights of male kidneys were increased following 13 weeks, 6 months and 1 year of exposure to MTBE concentrations of 7.5 mg ml(-1) or greater. Kidney wet weights were increased in females at MTBE concentrations of 15 mg ml(-1) for 13 weeks. Tertiary-butyl alcohol blood levels increased linearly with dose in males and females following 1 year of exposure. Chronic progressive nephropathy (CPN), of minimal to mild severity, increased in males, but not females, with 1 year of MTBE exposure. In summary, exposure of Wistar rats to MTBE in the drinking water resulted in minimal exposure-related effects including limited renal changes in male rats suggestive of α(2u)-globulin nephropathy following 13 weeks of exposure and an exacerbation of CPN in males at the end of 1 year of exposure. PMID:22833177

  2. A preliminary assessment of the occurrence and possible sources of MTBE in ground water of the United States, 1993-94

    USGS Publications Warehouse

    Squillace, P.J.

    1995-01-01

    The 1990 Clean Air Act Amendments require fuel oxygenates to be added to gasoline used in some metropolitan areas to reduce atmospheric concen- trations of carbon monoxide or ozone. Methyl tert-butyl ether (MTBE), is the most commonly used fuel oxygenate and is a relatively new gasoline additive. Nevertheless, out of 60 volatile organic chemicals analyzed, MTBE was the second most frequently detected chemical in samples of shallow ambient ground water from urban areas that were collected during 1993-94 as part of the U.S. Geological Survey's National Water-Quality Assessment program. Samples were collected from 5 drinking-water wells, 12 springs, and 193 monitoring wells in urban areas. No MTBE was detected in drinking-water wells. At a reporting level of 0.2 ug/L (micrograms per liter), MTBE was detected most frequently in shallow ground water from urban areas (27 percent of 210 wells and springs sampled in 8 areas) as compared to shallow ground water from agricultural areas (1.3 percent of 549 wells sampled in 21 areas) or deeper ground water from major aquifers (1 percent of 412 wells sampled in 9 areas). Only 3 percent of the shallow wells sampled in urban areas had concentrations of MTBE that exceed 20 ug/L, which is the estimated lower limit of the U.S. Environmental Protection Agency draft drinking-water health advisory. Because MTBE is persistent and mobile in ground water, it can move from shallow to deeper aquifers with time. In shallow urban ground water, MTBE generally was not found with benzene, toluene, ethylbenzene, or xylenes (BTEX) compounds which commonly are associated with gasoline spills. This disassociation causes uncertainty as to the source of MTBE. Possible sources of MTBE in ground water include point sources, such as leaking storage tanks, and nonpoint sources, such as recharge of precipitation and storm-water runoff.

  3. MTBE and priority contaminant treatment with high energy electron beam injection

    NASA Astrophysics Data System (ADS)

    Cooper, William J.; Nickelsen, Michael G.; Mezyk, Stephen P.; Leslie, Greg; Tornatore, Paul M.; Hardison, Wayne; Hajali, Paris A.

    2002-11-01

    A study was conducted to examine the removal of methyl tert-butyl ether (MTBE) and 15 other organic compounds, as well as perchlorate ion, in waters of different quality. The 15 organic compounds consisted of halogenated solvents (chlorination), disinfection by-products, pesticides, and nitrosodimethylamine (NDMA). These studies were conducted using a pilot scale 20 kW mobile electron beam system at Water Factory 21, Orange County, CA where wastewater is treated and re-injected into the ground as a barrier to salt water intrusion. Future applications for this treated water include water reuse. Ground water and treated wastewater, after having gone through a reverse osmosis-polishing step (RO permeate), were used to prepare mixtures of the compounds. Using fundamental radiation chemistry, it was possible to examine the factors effecting removal efficiency of all the compounds as well as MTBE destruction and reaction by-product formation and removal. All of the organic compounds were destroyed in the studies and we also observed the destruction of perchlorate ion in one of the waters.

  4. Mechanism of aerobic biological destabilisation of wool scour effluent emulsions.

    PubMed

    Poole, Andrew J; Cord-Ruwisch, Ralf; William Jones, F

    2005-07-01

    Wool scouring effluent is a highly polluted industrial wastewater in which the main pollutant, wool wax, is held in a stable oil-in-water emulsion by non-ionic detergent. The use of microbial action to cause emulsion destabilisation has been proposed as a new treatment strategy for this effluent stream. This strategy aims at improving aerobic treatment performance by physically removing the high-COD, slowly bio-degradable wool wax from the system without bio-degradation. The mechanism by which an aerobic-mixed culture destabilises the wool scouring effluent emulsion was investigated. Our results show that destabilisation is due to partial bio-degradation of both the scouring detergent and the wool wax. Cleavage of the wool wax esters was the first stage in wax degradation, when 40-50% of wax was de-emulsified. Over the same period, detergent degradation was low, at 7-21%. With further incubation, detergent degradation increased, aiding further breakdown of the emulsion. The degradation of the detergent, a nonylphenol ethoxylate, resulted in both a reduction in molar concentration (of up to 82%) and a shortening of the ethoxylate chain length. The latter reduced the hydrophile-lipophile balance (HLB) from 12 to approximately 7, thereby reducing the ability of the residual detergent to stabilise the emulsion. Analysis of the emulsified and de-emulsified wax fractions could not identify a group of compounds that were preferentially de-emulsified based on molecular weight or polarity. These findings will assist in using a de-emulsification strategy in both existing and new treatment systems in order to save on aeration costs and treatment times for biological treatment of this highly polluted wastewater. PMID:15979119

  5. ADVANCED OXIDATION PROCESSES (AOPS) FOR DESTRUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE -AN UNREGULATED CONTAMINANT) IN DRINKING WATER

    EPA Science Inventory

    Advanced oxidation processes (AOPs) provide a promising treatment option for the destruction of MTBE directly in surface and ground waters. An ongoing study is evaluating the ability of three AOPs; hydrogen peroxide/ozone (H2O2/ O3), ultraviolet irradiation/ozone (UV/O3) and ultr...

  6. TOXICITY OF METHYL-TERT BYTYL ETHER (MTBE) TO PLANTS (AVENA SATIVA, ZEA MAYS, TRITICUM AESTIVUM, AND LACTUCA SATIVA)

    EPA Science Inventory

    Effects of Methyl tert-butyl ether (MTBE) on the germination of seeds and growth of the plant were studied in some laboratory experiments. Test plants were wild oat (Avena sative), sweet corn (Zea mays), wheat (Triticum aestivum), and lettuce (Lactuca sativa). Seed germination,...

  7. Effects of Temperature and Acidic Pre-Treatment on Fenton-Driven Oxidation of MTBE-Spent Granular Activated Carbon

    EPA Science Inventory

    Temperature-dependent mechanisms in the Fenton-driven chemical oxidation of methyl tert-butyl ether (MTBE)-spent granular activated carbon (GAC) was investigated. Prior to iron (Fe) amendment to the GAC, acid-treatment altered the surface chemistry of the GAC and lowered the pH ...

  8. Fenton-driven regeneration of MTBE-spent granular activated carbon - Effects of particle size and Iron Amendment Procedures

    EPA Science Inventory

    Fenton-driven regeneration of spent granular activated carbon (GAC) is a technology being developed to regenerate organic contaminant-spent GAC. Here, the effect of GAC particle size (>2 mm to <0.35 mm) on Fenton-driven oxidation of methyl tert-butyl ether (MTBE)-spent GAC was ev...

  9. Effects on temperature and acidic pre-treatment on Fenton-driven oxidation of MTBE-spent granular activated carbon

    EPA Science Inventory

    Temperature-dependent mechanisms in the Fenton-driven chemical oxidation of methyl tert-butyl ether (MTBE)-spent granular activated carbon (GAC) was investigated. Prior to iron (Fe) amendment to the GAC, acid-treatment altered the surface chemistry of the GAC and lowered the p...

  10. Alveolar breath sampling and analysis to assess exposures to methyl tertiary butyl ether (MTBE) during motor vehicle refueling

    SciTech Connect

    Lindstrom, A.B.; Pleil, J.D.

    1996-07-01

    In this study we present a sampling and analytical methodology that can be used to assess consumers` exposures to methyl tertiary butyl ether (MTBE) that may result from routine vehicle refueling operations. The method is based on the collection of alveolar breath samples using evacuated one-liter stainless steel canisters and analysis using a gas chromatograph-mass spectrometer equipped with a patented `valveless` cryogenic preconcentrator. To demonstrate the utility of this approach, a series of breath samples was collected from two individuals (the person pumping the fuel and a nearby observer) immediately before and for 64 min after a vehicle was refueled with premium grade gasoline. Results demonstrate low levels of MTBE in both subjects` breaths before refueling, and levels that increased by a factor of 35 to 100 after the exposure. Breath elimination models fitted to the post exposure measurements indicate that the half-life of MTBE in the first physiological compartment was between 1.3 and 2.9 min. Analysis of the resulting models suggests that breath elimination of MTBE during the 64 min monitoring period was approximately 155 {mu}g for the refueling subject while it was only 30 {mu}g for the nearby observer. This analysis also shows that the post exposure breath elimination of other gasoline constituents was consistent with previously published observations. 20 refs., 3 figs., 4 tabs.

  11. Evaluation of a UV/Ozone Treatment Process for Removal of MTBE in Groundwater Supplies in New Mexico

    EPA Science Inventory

    EPA’s Office of Research and Development is funding pilot-scale studies on MTBE contaminated groundwater using UV/ozone treatment technology (254 nm UV, 5.8 mg/L ozone). The pilot-scale treatment system consists of a GW well pump, a feed tank, a pretreatment system (water softene...

  12. ANAEROBIC DEGRADATION OF MTBE TO TBA IN GROUND WATER AT GASOLINE SPILL SITES IN ORANGE COUNTY, CALIFORNIA

    EPA Science Inventory

    Although tert-Butyl Alcohol (TBA) has not been used as a fuel oxygenate in Orange County, California, the concentrations of TBA in ground water at gasoline spill sites are high compared to the concentrations of the conventional fuel oxygenate Methyl tert-Butyl Ether (MTBE). In t...

  13. CO-OCCURRENCE OF METHYL- TERT-BUTYL ETHER (MTBE) AND BTEX COMPOUNDS AT MARINAS IN A LARGE RESEVOIR

    EPA Science Inventory

    Methyl tert-butyl ether (MTBE) is released into the environment as one of some gasoline components, not as a pure compound. BTEX compounds (benzene, tolune, ethylbenzene, and xylenes) are major volatile constituents found in gasoline and are water soluble and mobile. This study...

  14. MTBE DEGRADATION USING FENTON'S REAGENT: THE EFFECT OF FERROUS AND FERRIC IRON MIXTURES ON THE EFFICIENCY OF THE OVERALL REACTION

    EPA Science Inventory

    The gasoline additive MTBE has been extensively used in the U.S. since the late 70's to increase the octane rating in reformulated gasoline, replacing toxic organo-lead compounds. However, its use was boosted during the late 80's, when the study of additional physico-chemical pro...

  15. MTBE DEGRADATION USING FENTON REAGENT: THE EFFECT OF FERROUS AND FERRIC IRON MIXTURES ON THE EFFICIENCY OF THE OVERALL REACTION

    EPA Science Inventory

    The gasoline additive MTBE has been extensively used in the U.S. since the late 70's to increase the octane rating in reformulated gasoline, replacing toxic organo-lead compounds. However, its use was boosted during the late 80's, when the study of additional physico-chemical pro...

  16. EVALUATION OF METHYL TERT-BUTYL ETHER (MTBE) AS AN INTERFERENCE ON COMMERCIAL BREATH-ALCOHOL ANALYZERS

    EPA Science Inventory

    Anecdotal reports suggest that high environmental or occupational exposures to the fuel oxygenate methyl tert-butyl ether (MTBE) may result in breath concentrations that are sufficiently elevated to cause a false positive on commercial breath-alcohol analyzers. We evaluated th...

  17. Evaluation of a UV/Ozone Treatment Process for Removal of MTBE in Groundwater Supplies in New Mexico

    EPA Science Inventory

    EPA’s Office of Research and Development is funding pilot-scale studies on MTBE contaminated groundwater using UV/ozone treatment technology (254 nm UV, 5.8 mg/L ozone). The pilot-scale treatment system consists of a GW well pump, a feed tank, a pretreatment system (water soften...

  18. Relative quantitative PCR to assess bacterial community dynamics during biodegradation of diesel and biodiesel fuels under various aeration conditions.

    PubMed

    Cyplik, Paweł; Schmidt, Marcin; Szulc, Alicja; Marecik, Roman; Lisiecki, Piotr; Heipieper, Hermann J; Owsianiak, Mikołaj; Vainshtein, Mikhail; Chrzanowski, Łukasz

    2011-03-01

    The degradation of diesel fuel, B20 blend and biodiesel in liquid cultures by a seven-member bacterial consortium was compared under conditions with full aeration or with limited aeration with nitrate added as main electron acceptor. Community dynamics was assessed employing real-time PCR and the ddCt method for relative quantification. Biodegradation rates increased with increasing biodiesel content, but were significantly reduced under conditions with nitrate. Despite large variations in biodegradation rates, magnitude changes in population numbers were typically observed only from zero to one order, regardless the type of fuel and electron acceptor. Only Comamonadaceae and Variovorax sp. distinctly preferred aerobic conditions, and during aerobic growth showed suppression as fuel contained more biodiesel. Thus, the consortium is relatively stable and most of the degraders can shift their metabolism from hydrocarbons to biodiesel. The stability of the consortium is of interest in the context of biodiesel-mediated biodegradation of petroleum hydrocarbons. PMID:21239170

  19. Soil aeration to achieve co-metabolic biodegradation of chlorinated solvents in the presence of inducer compounds

    SciTech Connect

    Eisenbeis, J.J.; Bourquin, A.W.

    1995-12-31

    A chemical distribution facility in Denver has been found to have soil and ground water contaminated with a wide variety of organic compounds, primarily toluene and chlorinated solvents, and their breakdown products. Since toluene and chlorobenzenes (both present at the site) have been shown to be inducers for an aerobic enzyme pathway that can degrade trichloroethene (TCE), 1,2-dichloroethene (DCE) and vinyl chloride, field and laboratory studies are being conducted to determine if cometabolic aerobic biodegradation of these and other compounds is occurring in soils that have been aerated with soil vapor extraction (SVE). Studies summarized in this paper include in situ respiration tests to estimate overall biodegradation rate in aerated soils within the influence of a SVE system, sampling to determine if in situ biodegradation of chlorinated volatile organic compounds in ground water has occurred, and a laboratory column study simulating bioventing of unremediated soils.

  20. Biodegradation of rhamnolipids in liquid cultures: effect of biosurfactant dissipation on diesel fuel/B20 blend biodegradation efficiency and bacterial community composition.

    PubMed

    Chrzanowski, Łukasz; Dziadas, Mariusz; Ławniczak, Łukasz; Cyplik, Paweł; Białas, Wojciech; Szulc, Alicja; Lisiecki, Piotr; Jeleń, Henryk

    2012-05-01

    Bacterial utilization of rhamnolipids during biosurfactant-supplemented biodegradation of diesel and B20 (20% biodiesel and 80% diesel v/v) fuels was evaluated under conditions with full aeration or with nitrate and nitrite as electron acceptors. Rhamnolipid-induced changes in community dynamics were assessed by employing real-time PCR and the ddCt method for relative quantification. The experiments with rhamnolipids at 150 mg/l, approx. double critical micelle concentration (CMC) and diesel oil confirmed that rhamnolipids were readily degraded by a soil-isolated consortium of hydrocarbon degraders in all samples, under both aerobic and nitrate-reducing conditions. The presence of rhamnolipids increased the dissipation rates for B20 constituents under aerobic conditions, but did not influence the biodegradation rate of pure diesel. No effect was observed under nitrate-reducing conditions. The biodegradation of rhamnolipids did not favor the growth of any specific consortium member, which proved that the employed biosurfactant did not interfere with the microbial equilibrium during diesel/biodiesel biodegradation. PMID:22366606

  1. Biodegradable Polymers for the Environment

    NASA Astrophysics Data System (ADS)

    Gross, Richard A.; Kalra, Bhanu

    2002-08-01

    Biodegradable polymers are designed to degrade upon disposal by the action of living organisms. Extraordinary progress has been made in the development of practical processes and products from polymers such as starch, cellulose, and lactic acid. The need to create alternative biodegradable water-soluble polymers for down-the-drain products such as detergents and cosmetics has taken on increasing importance. Consumers have, however, thus far attached little or no added value to the property of biodegradability, forcing industry to compete head-to-head on a cost-performance basis with existing familiar products. In addition, no suitable infrastructure for the disposal of biodegradable materials exists as yet.

  2. Evaluation of an aerobic treatment for olive mill wastewater detoxification.

    PubMed

    El Hajjouji, Houda; El Fels, Loubna; Pinelli, Eric; Barje, Farid; El Asli, Abdelghani; Merlina, Georges; Hafidi, Mohamed

    2014-01-01

    Olive mill wastewater (OMWW) is a by-product of the olive oil extraction industry. Its dumping creates severe environmental problems in the Mediterranean countries. The phytoxicity of OMWW is due to the phenolic substances and is evaluated through a genotoxicity method. An aerobic treatment of OMWW was conducted during 45 days. Different concentrations of raw and treated OMWW were tested using the Vicia faba micronuclei test. Results showed that raw OMWW induced significant micronuclei formation at 10% of OMWW dilution. At 20% of dilution, no mitosis was recorded. The 45 days aerobic treatment OMWW showed an important decrease in the genotoxicity and also in the toxicity that was observed at 10% and 20% OMWW dilution. This could be correlated with the biodegradation of 76% of the total phenols. Indeed, qualitative analysis by high performance liquid chromatography shows the disappearance of the majority of phenolic compounds after 45 days of treatment. This study was completed by an agricultural test with V. faba plant. Data showed significant growth yield of 36.3% and 29.9% after being irrigated with 5 and 10 t/ha, respectively. These results supported the positive role of aerobic treatment on OMWW and their capacity to ameliorate the agronomic potential of these effluents. PMID:25244133

  3. Pilot-scale ISCO treatment of a MtBE contaminated site using a Fenton-like process.

    PubMed

    Innocenti, Ivan; Verginelli, Iason; Massetti, Felicia; Piscitelli, Daniela; Gavasci, Renato; Baciocchi, Renato

    2014-07-01

    This paper reports about a pilot-scale feasibility study of In-Situ Chemical Oxidation (ISCO) application based on the use of stabilized hydrogen peroxide catalyzed by naturally occurring iron minerals (Fenton-like process) to a site formerly used for fuel storage and contaminated by MtBE. The stratigraphy of the site consists of a 2-3 meter backfill layer followed by a 3-4 meter low permeability layer, that confines the main aquifer, affected by a widespread MtBE groundwater contamination with concentrations up to 4000 μg/L, also with the presence of petroleum hydrocarbons. The design of the pilot-scale treatment was based on the integration of the results obtained from experimental and numerical modeling accounting for the technological and regulatory constraints existing in the site to be remediated. In particular, lab-scale batch tests allowed the selection of the most suitable operating conditions. Then, this information was implemented in a numerical software that allowed to define the injection and monitoring layout and to predict the propagation of hydrogen peroxide in groundwater. The pilot-scale field results confirmed the effective propagation of hydrogen peroxide in nearly all the target area (around 75 m(2) using 3 injection wells). As far as the MtBE removal is concerned, the ISCO application allowed us to meet the clean-up goals in an area of 60 m(2). Besides, the concentration of TBA, i.e. a potential by-product of MtBE oxidation, was actually reduced after the ISCO treatment. The results of the pilot-scale test suggest that ISCO may be a suitable option for the remediation of the groundwater plume contaminated by MtBE, providing the background data for the design and cost-estimate of the full-scale treatment. PMID:24518270

  4. Partial nitritation and o-cresol removal with aerobic granular biomass in a continuous airlift reactor.

    PubMed

    Jemaat, Zulkifly; Suárez-Ojeda, María Eugenia; Pérez, Julio; Carrera, Julián

    2014-01-01

    Several chemical industries produce wastewaters containing both, ammonium and phenolic compounds. As an alternative to treat this kind of complex industrial wastewaters, this study presents the simultaneous partial nitritation and o-cresol biodegradation in a continuous airlift reactor using aerobic granular biomass. An aerobic granular sludge was developed in the airlift reactor for treating a high-strength ammonium wastewater containing 950 ± 25 mg N-NH4(+) L(-1). Then, the airlift reactor was bioaugmented with a p-nitrophenol-degrading activated sludge and o-cresol was added progressively to the ammonium feed to achieve 100 mg L(-1). The results showed that stable partial nitritation and full biodegradation of o-cresol were simultaneously maintained obtaining a suitable effluent for a subsequent anammox reactor. Moreover, two o-cresol shock-load events with concentrations of 300 and 1000 mg L(-1) were applied to assess the capabilities of the system. Despite these shock load events, the partial nitritation process was kept stable and o-cresol was totally biodegraded. Fluorescence in situ hybridization technique was used to identify the heterotrophic bacteria related to o-cresol biodegradation and the ammonia oxidising bacteria along the granules. PMID:24140352

  5. Monitoring biodegradation of hydrocarbons by stable isotope fractionation

    NASA Astrophysics Data System (ADS)

    Dorer, Conrad; Fischer, Anko; Herrmann, Steffi; Richnow, Hans-Hermann; Vogt, Carsten

    2010-05-01

    In the last decade, several studies have demonstrated that stable isotope tools are highly applicable for monitoring anaerobic biodegradation processes. An important methodological approach is to characterize distinct degradation pathways with respect to the specific mechanism of C-H-bond cleavage and to quantify the extent of biodegradation by compound specific isotope analysis (CSIA). Here, enrichment factors (ɛbulk) needed for a CSIA field site approach must be determined in laboratory reference experiments. Recent research results from different laboratories have shown that single ɛbulk values for similar degradation pathways can be highly variable; thus, the use of two-dimensional compound specific isotope analysis (2D-CSIA) has been encouraged for characterizing biodegradation pathways more precisely. 2D-CSIA for hydrocarbons can be expressed by the slope of the linear regression for hydrogen versus carbon discrimination known as lambda ≈ ɛHbulk/ɛCbulk. We determined the carbon and hydrogen isotope fractionation for the biodegradation of benzene, toluene and xylenes by various reference cultures. Specific enzymatic reactions initiating different biodegradation pathways could be distinguished by 2D-CSIA. For the aerobic di- and monohydroxylation of the benzene ring, lambda values always lower than 9 were observed. Enrichment cultures degrading benzene anaerobically produced significant different values: lambda values between 8-19 were oberved for nitrate-reducing consortia, whereas sulfate-reducing and methanogenic consortia showed always lambda values greater than 20 [1,2]. The observed variations suggest that (i) aerobic benzene biodegradation can be distinguished from anaerobic biodegradation, and (ii) that more than a single mechanism seems to exist for the activation of benzene under anoxic conditions. lambda values for anaerobic toluene degradation initiated by the enzyme benzylsuccinate synthase (BSS) ranged from 4 to 41, tested with strains using

  6. Sorption and biodegradation of selected benzotriazoles and hydroxybenzothiazole in activated sludge and estimation of their fate during wastewater treatment.

    PubMed

    Mazioti, Aikaterini A; Stasinakis, Athanasios S; Gatidou, Georgia; Thomaidis, Nikolaos S; Andersen, Henrik R

    2015-07-01

    Biodegradation of benzotriazole (BTR), 5-chlorobenzotriazole (CBTR), xylytriazole (XTR), 4-methyl-1H-benzotriazole (4TTR), 5-methy-1H-lbenzotriazole (5TTR) and 2-hydroxybenzothiazole (OHBTH) was studied in activated sludge batch experiments under aerobic and anoxic conditions, presence of organic substrate and different sludge residence times (SRTs). Their sludge-water distribution coefficients were also calculated in sorption experiments and ranged between 87 and 220 L kg(-1). Significant biodegradation of BTR, CBTR, XTR and OHBTH was observed in all biotic experiments. Half-life values ranged between 23 and 45 h (BTR), 18 and 47 h (CBTR), 14 and 26 h (XTR), 6.5 and 24 h (OHBTH). The addition of substrate did not suppress biodegradation kinetics; whereas in some cases accelerated biodegradation of microcontaminants. Except for CBTR, no effect of SRT on biodegradation constants was observed. Prediction of micropollutants removal in Sewage Treatment Plants (STPs) indicated that they will be partially removed, mainly due to aerobic biodegradation. Higher removal is expected at STPs operating at higher SRT and higher suspended solids concentrations. PMID:25828067

  7. Ozone/UV treatment to enhance biodegradation of surfactants in industrial wastewater. CRADA final report

    SciTech Connect

    Cline, J.E.; Sullivan, P.F.; Lovejoy, M.A.; Collier, J.; Adams, C.D.

    1996-10-01

    The new owners of a surfactant manufacturing plant wanted to triple production but were limited by the plant`s wastewater treatment capacity. Mass balance calculations indicated that little aerobic biodegradation was occurring in the plant`s wastewater treatment system. Literature reviews and laboratory tests confirmed that as much as 60% of the plant`s products might resist aerobic biodegradation. Overall chemical losses, both solid and aqueous, were estimated at 3.8% of theoretical. Organic loadings to the wastewater treatment system were 170 kg/d of which 50 kg/d reached the biological treatment system. Pollution prevention measures have allowed a > 20% increase in production levels with a > 30% decrease in effluent volume and no increase in discharge of chemical oxygen demand (COD). A new dissolved air flotation (DAF) system removes 70% of the organic loading. Sludge volumes are lower by an order of magnitude than with the clarifier/drum-filter process it replaced.

  8. BIODEGRADATION - MONITORED NATURAL ATTENUATION (MNA) FOR OXYGENATES: HOW IT EVOLVED, WHY IT OCCURS AND STABLE ISOTOPES

    EPA Science Inventory

    The organisms that degrade MtBE under anaerobic conditions are evolved to acquire energy for growth by using molecular hydrogen and carbonate ion to cleave methyl ether bonds. Methyl ether bonds are common in nature and the bond also occurs in MTBE. MTBE in contaminated ground...

  9. BIODEGRADATION OF METHYL TERT-BUTYL ETHER AND BTEX AT VARYING HYDRAULIC RETENTION TIMES

    EPA Science Inventory

    The feasibility of biologically degrading methyl tert-butyl ether (MTBE) contaminated groundwater is dependent on the ability to degrade MTBE and its byproducts in the presence of other gasoline contaminants. This study investigates a mixed culture degrading both MTBE and benzene...

  10. Sequential anaerobic-aerobic degradation of indigenous PCBs in a contaminated soil matrix

    SciTech Connect

    Klasson, K.T.; Reeves, M.E.; Evans, B.S.; Dudley, C.A.

    1994-12-31

    Many industrial locations, including the US Department of Energy`s, have identified needs for treatment of polychlorinated biphenyl (PCB) wastes and remediation of PCB-contaminated sites. Biodegradation of PCBs is a potentially effective technology for the treatment of PCB-contaminated soils and sludges; however, a practicable remediation technology has not yet been demonstrated. A biological treatment technology is likely to consist of an anaerobic fermentation step in which PCB dechlorination takes place producing PCBs with fewer chlorines. These products are then more susceptible to aerobic mineralization. In laboratory experiments, soil slurry bioreactors inoculated with microorganisms extracted from PCB-contaminated sediments from the Hudson River and Woods Pond have been used to obtain anaerobic dechlorination of PCBs in soil slurry reactors. The anaerobic dechlorination was followed by qualitative estimation of the effect of aerobic fermentation of the dechlorination products based on literature data. The sequential anaerobic-(simulated) aerobic treatment constituted an improvement compared anaerobic treatment alone.

  11. Xenobiotic benzotriazoles--biodegradation under meso- and oligotrophic conditions as well as denitrifying, sulfate-reducing, and anaerobic conditions.

    PubMed

    Herzog, Bastian; Lemmer, Hilde; Huber, Bettina; Horn, Harald; Müller, Elisabeth

    2014-02-01

    The intensive use of benzotriazoles as corrosion inhibitors for various applications and their application in dishwasher detergents result in an almost omnipresence of benzotriazole (BTri), 4-methyl- and 5-methyl-benzotriazole (4-TTri and 5-TTri, respectively) in aquatic systems. This study aims on the evaluation of the biodegradation potential of activated sludge communities (ASCs) toward the three benzotriazoles regarding aerobic, anoxic, and anaerobic conditions and different nutrients. ASCs were taken from three wastewater treatment plants with different technologies, namely, a membrane bioreactor (MBR-MH), a conventional activated sludge plant CAS-E (intermittent nitrification/denitrification), and CAS-M (two-stage activated sludge treatment) and used for inoculation of biodegradation setups. All ASCs eliminated up to 30 mg L(-1) 5-TTri and BTri under aerobic conditions within 2-7 and 21-49 days, respectively, but not under anoxic or anaerobic conditions. 4-TTri was refractory at all conditions tested. Significant differences were observed for BTri biodegradation with non-acclimated ASCs from MBR-MH with 21 days, CAS-E with 41 days, and CAS-M with 49 days. Acclimated ASCs removed BTri within 7 days. Furthermore, different carbon and nitrogen concentrations revealed that nitrogen was implicitly required for biodegradation while carbon showed no such effect. The fastest biodegradation occurred for 5-TTri with no need for acclimatization, followed by BTri. BTri showed sludge-specific biodegradation patterns, but, after sludge acclimation, was removed with the same pattern, regardless of the sludge used. Under anaerobic conditions in the presence of different electron acceptors, none of the three compounds showed biological removal. Thus, presumably, aerobic biodegradation is the major removal mechanism in aquatic systems. PMID:24136576

  12. Methyl tert-butyl ether (MTBE) detected in abnormally high concentrations in postmortem blood and urine from two persons found dead inside a car containing a gasoline spill.

    PubMed

    Karinen, Ritva; Vindenes, Vigdis; Morild, Inge; Johnsen, Lene; Le Nygaard, Ilah; Christophersen, Asbjørg S

    2013-09-01

    Two deep frozen persons, a female and a male, were found dead in a car. There had been an explosive fire inside the car which had extinguished itself. On the floor inside the car were large pools of liquid which smelled of gasoline. The autopsy findings and routine toxicological analyses could not explain the cause of death. Carboxyhemoglobin levels in the blood samples were <10%. Analysis with a headspace gas chromatography revealed methyl tert-butyl ether (MTBE) concentrations of 185 mg/L (female victim) and 115 mg/L (male victim) in peripheral blood. The urine MTBE concentrations were 150 mg/L and 256 mg/L, respectively. MTBE is a synthetic chemical which is added to gasoline as a fuel oxygenate. Gasoline poisoning is likely to be the cause of the death in these two cases, and MTBE can be a suitable marker of gasoline exposure, when other volatile components have vaporized. PMID:23879346

  13. Biodegradable pectin/clay aerogels.

    PubMed

    Chen, Hong-Bing; Chiou, Bor-Sen; Wang, Yu-Zhong; Schiraldi, David A

    2013-03-13

    Biodegradable, foamlike materials based on renewable pectin and sodium montmorillonite clay were fabricated through a simple, environmentally friendly freeze-drying process. The addition of multivalent cations (Ca(2+) and Al(3+)) resulted in apparent cross-linking of the polymer and enhancement of aerogel properties. The compressive properties increased as the solid contents (both pectin and clay) increased; moduli in the range of 0.04-114 MPa were obtained for materials with bulk densities ranging from 0.03 g/cm(3) to 0.19 g/cm(3), accompanied by microstructural changes from a lamellar structure to a cellular structure. Biodegradability of the aerogels was investigated by detecting CO2 release for 4 weeks in compost media. The results revealed that pectin aerogels possess higher biodegradation rates than wheat starch, which is often used as a standard for effective biodegradation. The addition of clay and multivalent cations surprisingly increased the biodegradation rates. PMID:23406325

  14. Biodegradation of phenol, salicylic acid, benzenesulfonic acid, and iomeprol by Pseudomonas fluorescens in the capillary fringe.

    PubMed

    Hack, Norman; Reinwand, Christian; Abbt-Braun, Gudrun; Horn, Harald; Frimmel, Fritz H

    2015-12-01

    Mass transfer and biological transformation phenomena in the capillary fringe were studied using phenol, salicylic acid, benzenesulfonic acid, and the iodinated X-ray contrast agent iomeprol as model organic compounds and the microorganism strain Pseudomonas fluorescens. Three experimental approaches were used: Batch experiments (uniform water saturation and transport by diffusion), in static columns (with a gradient of water saturation and advective transport in the capillaries) and in a flow-through cell (with a gradient of water saturation and transport by horizontal and vertical flow: 2-dimension flow-through microcosm). The reactors employed for the experiments were filled with quartz sand of defined particle size distribution (dp=200...600 μm, porosity ε=0.42). Batch experiments showed that phenol and salicylic acid have a high, whereas benzenesulfonic acid and iomeprol have a quite low potential for biodegradation under aerobic conditions and in a matrix nearly close to water saturation. Batch experiments under anoxic conditions with nitrate as electron acceptor revealed that the biodegradation of the model compounds was lower than under aerobic conditions. Nevertheless, the experiments showed that the moisture content was also responsible for an optimized transport in the liquid phase of a porous medium. Biodegradation in the capillary fringe was found to be influenced by both the moisture content and availability of the dissolved substrate, as seen in static column experiments. The gas-liquid mass transfer of oxygen also played an important role for the biological activity. In static column experiments under aerobic conditions, the highest biodegradation was found in the capillary fringe (e.g. βt/β0 (phenol)=0 after t=6 d) relative to the zone below the water table and unsaturated zone. The highest biodegradation occurred in the flow-through cell experiment where the height of the capillary fringe was largest. PMID:26529301

  15. Biodegradation of phenol, salicylic acid, benzenesulfonic acid, and iomeprol by Pseudomonas fluorescens in the capillary fringe

    NASA Astrophysics Data System (ADS)

    Hack, Norman; Reinwand, Christian; Abbt-Braun, Gudrun; Horn, Harald; Frimmel, Fritz H.

    2015-12-01

    Mass transfer and biological transformation phenomena in the capillary fringe were studied using phenol, salicylic acid, benzenesulfonic acid, and the iodinated X-ray contrast agent iomeprol as model organic compounds and the microorganism strain Pseudomonas fluorescens. Three experimental approaches were used: Batch experiments (uniform water saturation and transport by diffusion), in static columns (with a gradient of water saturation and advective transport in the capillaries) and in a flow-through cell (with a gradient of water saturation and transport by horizontal and vertical flow: 2-dimension flow-through microcosm). The reactors employed for the experiments were filled with quartz sand of defined particle size distribution (dp = 200…600 μm, porosity ε = 0.42). Batch experiments showed that phenol and salicylic acid have a high, whereas benzenesulfonic acid and iomeprol have a quite low potential for biodegradation under aerobic conditions and in a matrix nearly close to water saturation. Batch experiments under anoxic conditions with nitrate as electron acceptor revealed that the biodegradation of the model compounds was lower than under aerobic conditions. Nevertheless, the experiments showed that the moisture content was also responsible for an optimized transport in the liquid phase of a porous medium. Biodegradation in the capillary fringe was found to be influenced by both the moisture content and availability of the dissolved substrate, as seen in static column experiments. The gas-liquid mass transfer of oxygen also played an important role for the biological activity. In static column experiments under aerobic conditions, the highest biodegradation was found in the capillary fringe (e.g. βt/β0 (phenol) = 0 after t = 6 d) relative to the zone below the water table and unsaturated zone. The highest biodegradation occurred in the flow-through cell experiment where the height of the capillary fringe was largest.

  16. Methods for Assessment of Biodegradability of Plastic Films in Soil †

    PubMed Central

    Yabannavar, Asha V.; Bartha, Richard

    1994-01-01

    Traditional and novel techniques were tested and compared for their usefulness in evaluating biodegrad-ability claims made for newly formulated “degradable” plastic film products. Photosensitized polyethylene (PE), starch-PE, extensively plasticized polyvinyl chloride (PVC), and polypropylene (PP) films were incorporated into aerobic soil. Biodegradation was measured for 3 months under generally favorable conditions. Carbon dioxide evolution, residual weight recovery, and loss of tensile strength measurements were supplemented, for some films, by gas chromatographic measurements of plasticizer loss and gel permeation chromatographic (GPC) measurement of polymer molecular size distribution. Six- and 12-week sunlight exposures of photosensitized PE films resulted in extensive photochemical damage that failed to promote subsequent mineralization in soil. An 8% starch-PE film and the plasticized PVC film evolved significant amounts of CO2 in biodegradation tests and lost residual weight and tensile strength, but GPC measurements demonstrated that all these changes were confined to the additives and the PE and PVC polymers were not degraded. Carbon dioxide evolution was found to be a useful screening tool for plastic film biodegradation, but for films with additives, polymer biodegradation needs to be confirmed by GPC. Photochemical cross-linking of polymer strands reduces solubility and may interfere with GPC measurements of polymer degradation. PMID:16349408

  17. Aerobic bioremediation of 1,2 dichloroethane and vinyl chloride at field scale

    NASA Astrophysics Data System (ADS)

    Davis, Gregory B.; Patterson, Bradley M.; Johnston, Colin D.

    2009-06-01

    Aerobic bioremediation of 1,2 dichloroethane (1,2 DCA) and vinyl chloride (VC) was evaluated at field scale in a layered, silty and fine-sand anaerobic aquifer. Maximum concentrations of 1,2 DCA (2 g/L) and VC (0.75 g/L) in groundwater were within 25% and 70% of pure compound solubility, respectively. Aerobic conditions were induced by injecting air into sparging wells screened 20.5-21.5 m below ground (17-18 m below the water table). Using a cycle of 23 h of air injection followed by three days of no air injection, fifty days of air injection were accumulated over a 12 month period which included some longer periods of operational shutdown. Oxygen and volatile organic compound probes, and multilevel samplers were used to determine changes of the primary contaminants and the associated inorganic chemistry at multiple locations and depths. Air (oxygen) was distributed laterally up to 25 m from the sparge points, with oxygen partial pressures up to 0.7 atmospheres (28-35 mg/L in groundwater) near to the sparge points. The dissolved mass of 1,2 DCA and VC was reduced by greater than 99% over the 590 m 2 trial plot. Significantly, pH declined from nearly 11 to less than 9, and sulfate concentrations increased dramatically, suggesting the occurrence of mineral sulfide (e.g., pyrite) oxidation. Chloride and bicarbonate (aerobic biodegradation by-products) concentration increases were used to estimate that 300-1000 kg of chlorinated hydrocarbons were biodegraded, although the ratio of 1,2 DCA to VC that was biodegraded remained uncertain. The mass biodegraded was comparable but less than the 400-1400 kg of chlorinated compounds removed from the aqueous phase within a 10,000 m 3 volume of the aquifer. Due to the likely presence of non-aqueous phase liquid, the relative proportion of volatilisation compared to biodegradation could not be determined. The aerobic biodegradation rates were greater than those previously estimated from laboratory-based studies.

  18. Boost refining profits by converting surplus butadiene to valuable feedstocks for MTBE and/or alkylation

    SciTech Connect

    Nocca, J.L. ); Hennico, A.; Cosyns, J.; Torck, B. )

    1994-01-01

    Ethylene plants produce a C4 butadiene-rich cut as a by-product. Although it has been a highly valued chemical intermediate for a long time, butadiene is now in over supply due to the installation of new steam cracking plants and the growing use of naphtha, the main butadiene generator, as feedstock. In the meantime, the demand for alkylate and ethers has increased steadily to produce environmentally friendly gasoline. This paper presents processes developed by IFP to convert surplus butadiene into ethers or alkylate for gasoline production. The first process transforms the butadiene-rich stream into a butenes-rich stream, an ideal alkylation feedstock. The second process generates isobutene from the butenes stream by skeletal isomerization for MTBE production.

  19. Coast Guard exposure to gasoline, MTBE, and benzene vapors during inspection of tank barges.

    PubMed

    Davenport, A C; Glynn, T J; Rhambarose, H

    2000-01-01

    A field study was conducted June through August 1996 in an attempt to quantify short-term exposure levels to Coast Guard personnel performing routine inspection activities aboard commercial tank barges carrying gasoline. Transfer and fleeting operations were monitored in the ports of Pittsburgh, Pa., Huntington, W.Va., Baton Rouge, La., and Galveston, Tex. A total of 43 personal and 68 area samples were analyzed for benzene and total hydrocarbons as gasoline ("gasoline"). Results can be summarized as follows: Personal exposure to benzene gave 15-min time-weighted-average (TWA) results ranging from <0.10 to 0.50 ppm. Area benzene levels ranged from <0.04 to 170 ppm. Personal monitoring for gasoline revealed a range of <2.0 to 590 mg/m3 with a GM of 23 mg/m3. Area sample results for gasoline ranged from 1.7 to 90,000 mg/m3. Twelve personal samples were collected for methyl-tert butyl ether (MTBE). Only two of these were above the limit of detection and had 15-min time-weighted averages of 22 ppm and 1.3 ppm. Eighteen MTBE area samples ranged in value from <3.0 to 38 ppm. Although none of the personal samples met or exceeded proposed or established short-term exposure standards, many of the area sampling results indicated that a significant risk of acute exposure exists in the vicinity of valves, pressure lines, and connections. This includes anticipated sources such as pressure vent valves as well as unexpected sources resulting from structural deficiencies onboard the vessels. These results further emphasize the value of safe work practices and proper vessel maintenance in controlling exposure to harmful chemicals. PMID:11192221

  20. Preparation of a biodegradable oil absorber and its biodegradation.

    PubMed

    Yoo, Su-Yong; Daud, Wan Mohd Ashri Wan; Lee, Min-Gyu

    2012-01-01

    The biodegradable oil absorption resin (B-PEHA) was prepared by suspension polymerization, and its preparation was confirmed by Fourier transform infrared analysis. The oil absorption capacities of the prepared B-PEHA were: chloroform 30.88, toluene 19.75, xylene, 18.78, THF 15.96, octane 11.43, hexane 9.5, diesel oil 12.80, and kerosene 13.79 g/g. The biodegradation of the prepared B-PEHA was also investigated by determination of reduced sugar produced after enzymatic hydrolysis, thermogravimetric analysis, and incubation with Aspergillus niger. The biodegradation of B-PEHA was ~18%. PMID:21909668

  1. Biodegradation of the High Explosive Hexanitrohexaazaiso-wurtzitane (CL-20)

    PubMed Central

    Karakaya, Pelin; Christodoulatos, Christos; Koutsospyros, Agamemnon; Balas, Wendy; Nicolich, Steve; Sidhoum, Mohammed

    2009-01-01

    The aerobic biodegradability of the high explosive CL-20 by activated sludge and the white rot fungus Phanerochaete chrysosporium has been investigated. Although activated sludge is not effective in degrading CL-20 directly, it can mineralize the alkaline hydrolysis products. Phanerochaete chrysosporium degrades CL-20 in the presence of supplementary carbon and nitrogen sources. Biodegradation studies were conducted using various nutrient media under diverse conditions. Variables included the CL-20 concentration; levels of carbon (as glycerol) and ammonium sulfate and yeast extract as sources of nitrogen. Cultures that received CL-20 at the time of inoculation transformed CL-20 completely under all nutrient conditions studied. When CL-20 was added to pre-grown cultures, degradation was limited. The extent of mineralization was monitored by the 14CO2 time evolution; up to 51% mineralization was achieved when the fungus was incubated with [14C]-CL-20. The kinetics of CL-20 biodegradation by Phanerochaete chrysosporium follows the logistic kinetic growth model. PMID:19440524

  2. Isolation and characterization of luminescent bacterium for sludge biodegradation.

    PubMed

    Zahaba, Maryam; Halmi, Mohd Izuan Effendi; Ahmad, Siti Aqlima; Shukor, Mohd Yunus; Syed, Mohd Arif

    2015-11-01

    Microtox is based on the inhibition of luminescence of the bacterium Vibrio fischeri by the toxicants. This technique has been accepted by the USEPA (United States Environmental Protection Agency) as a biomonitoring tool for remediation of toxicants such as hydrocarbon sludge. In the present study, a luminescent bacterium was isolated from yellow striped scad (Selaroides leptolepis) and was tentatively identified as Vibrio sp. isolate MZ. This aerobic isolate showed high luminescence activity in a broad range of temperature from 25 to 35 °C. In addition, optimal conditions for high bioluminescence activity in range of pH 7.5 to 8.5 and 10 gl(-1) of sodium chloride, 10 gl(-1) of peptone and 10 gl(-1) of sucrose as carbon source. Bench scale biodegradation 1% sludge (w/v) was set up and degradation was determined using gas chromatography with flame ionised detector (GC-FID). In this study, Rhodococcus sp. strain AQ5NOL2 was used to degrade the sludge. Based on the preliminary results obtained, Vibrio sp. isolate MZwas able to monitor the biodegradation of sludge. Therefore, Vibrio sp. isolate MZ has the potential to be used as a biomonitoring agent for biomonitoring of sludge biodegradation particularly in the tropical ranged environment. PMID:26688958

  3. The influence of iron on the biodegradation of benzene in soil microcosms

    SciTech Connect

    Poor, N.D.; Wheeler, E.; Novak, J.T.

    1996-12-31

    Iron was positively-correlated with benzene biodegradation rate in a statistically-significant multiple linear regression model of rates measured in aerobic soil microcosm experiments regressed with corresponding soil nitrate, phosphorus, iron, organic matter and sand content for 10 different previously uncontaminated Virginia subsurface soils. The addition of ferric chloride or ferric hydroxide to soil microcosms prepared with Alaga series sand and spiked with 10 mg/L initial benzene significantly increased the biodegradation rate in unamended experiments, but had no observable influence on biodegradation rates in experiments amended with ammonium phosphate and potassium phosphate. Unamended soil microcosms degraded 10 mg/L initial benzene in 10 days, iron-amended in 5 days, and nutrient-amended in 2 days.

  4. Biodegradation of Polypropylene Nonwovens

    NASA Astrophysics Data System (ADS)

    Keene, Brandi Nechelle

    The primary aim of the current research is to document the biodegradation of polypropylene nonwovens and filament under composting environments. To accelerate the biodegradat ion, pre-treatments and additives were incorporated into polypropylene filaments and nonwovens. The initial phase (Chapter 2) of the project studied the biodegradation of untreated polypropylene with/without pro-oxidants in two types of composting systems. Normal composting, which involved incubation of samples in food waste, had little effect on the mechanical properties of additive-free spunbond nonwovens in to comparison prooxidant containing spunbond nonwovens which were affected significantly. Modified composting which includes the burial of samples with food and compressed air, the polypropylene spunbond nonwovens with/without pro-oxidants displayed an extreme loss in mechanical properties and cracking on the surface cracking. Because the untreated spunbond nonwovens did not completely decompose, the next phase of the project examined the pre-treatment of gamma-irradiation or thermal aging prior to composting. After exposure to gamma-irradiation and thermal aging, polypropylene is subjected to oxidative degradation in the presence of air and during storage after irradiat ion. Similar to photo-oxidation, the mechanism of gamma radiation and thermal oxidative degradation is fundamentally free radical in nature. In Chapter 3, the compostability of thermal aged spunbond polypropylene nonwovens with/without pro-oxidant additives. The FTIR spectrum confirmed oxidat ion of the polypropylene nonwovens with/without additives. Cracking on both the pro-oxidant and control spunbond nonwovens was showed by SEM imaging. Spunbond polypropylene nonwovens with/without pro-oxidants were also preirradiated by gamma rays followed by composting. Nonwovens with/without pro-oxidants were severely degraded by gamma-irradiation after up to 20 kGy exposure as explained in Chapter 4. Furthermore (Chapter 5), gamma

  5. Laboratory and field verification of a method to estimate the extent of petroleum biodegradation in soil.

    PubMed

    Douglas, Gregory S; Hardenstine, Jeffery H; Liu, Bo; Uhler, Allen D

    2012-08-01

    We describe a new and rapid quantitative approach to assess the extent of aerobic biodegradation of volatile and semivolatile hydrocarbons in crude oil, using Shushufindi oil from Ecuador as an example. Volatile hydrocarbon biodegradation was both rapid and complete-100% of the benzene, toluene, xylenes (BTEX) and 98% of the gasoline-range organics (GRO) were biodegraded in less than 2 days. Severe biodegradation of the semivolatile hydrocarbons occurred in the inoculated samples with 67% and 87% loss of the diesel-range hydrocarbons (DRO) in 3 and 20 weeks, respectively. One-hundred percent of the naphthalene, fluorene, and phenanthrene, and 46% of the chrysene in the oil were biodegraded within 3 weeks. Percent depletion estimates based on C(30) 17α,21β(H)-hopane (hopane) underestimated the diesel-range organics (DRO) and USEPA 16 priority pollutant PAH losses in the most severely biodegraded samples. The C(28) 20S-triaromatic steroid (TAS) was found to yield more accurate depletion estimates, and a new hopane stability ratio (HSR = hopane/(hopane + TAS)) was developed to monitor hopane degradation in field samples. Oil degradation within field soil samples impacted with Shushufindi crude oil was 83% and 98% for DRO and PAH, respectively. The gas chromatograms and percent depletion estimates indicated that similar levels of petroleum degradation occurred in both the field and laboratory samples, but hopane degradation was substantially less in the field samples. We conclude that cometabolism of hopane may be a factor during rapid biodegradation of petroleum in the laboratory and may not occur to a great extent during biodegradation in the field. We recommend that the hopane stability ratio be monitored in future field studies. If hopane degradation is observed, then the TAS percent depletion estimate should be computed to correct for any bias that may result in petroleum depletion estimates based on hopane. PMID:22694180

  6. Biodegradation of Methyl tert-Butyl Ether by a Bacterial Pure Culture

    PubMed Central

    Hanson, Jessica R.; Ackerman, Corinne E.; Scow, Kate M.

    1999-01-01

    A bacterial strain, PM1, which is able to utilize methyl tert-butyl ether (MTBE) as its sole carbon and energy source, was isolated from a mixed microbial consortium in a compost biofilter capable of degrading MTBE. Initial linear rates of MTBE degradation by 2 × 106 cells ml−1 were 0.07, 1.17, and 3.56 μg ml−1 h−1 for initial concentrations of 5, 50, and 500 μg MTBE ml−1, respectively. When incubated with 20 μg of uniformly labeled [14C]MTBE ml−1, strain PM1 converted 46% to 14CO2 and 19% to 14C-labeled cells within 120 h. This yield is consistent with the measurement of protein accumulation at different MTBE concentrations from which was estimated a biomass yield of 0.18 mg of cells mg MTBE−1. Strain PM1 was inoculated into sediment core material collected from a contaminated groundwater plume at Port Hueneme, California, in which there was no evidence of MTBE degradation. Strain PM1 readily degraded 20 μg of MTBE ml−1 added to the core material. The rate of MTBE removal increased with additional inputs of 20 μg of MTBE ml−1. These results suggest that PM1 has potential for use in the remediation of MTBE-contaminated environments. PMID:10543787

  7. Biodegradation of PCBs

    SciTech Connect

    Kopec, R.I.

    1992-01-01

    PCBs were examined for biodegradability by a strain of Pseudomonas sp. designated E1, by a strain of Pseudomonas aeruginosa designated E2, and by a strain of Pseudomonas putida designated E3. The PCBs included Aroclor mixes from Aroclor 1221 to Aroclor 1268, and pure congeners ranging from monochlorobiphenyl to decachlorobiphenyl. These congeners represented all structural classes. Pure culture studies revealed that cells of E1 grew well on all structural classes of PCB congeners up to heptachlorobiphenyl, and all Aroclor mixes up to Aroclor 1260. Gas chromotographic analysis revealed that biphenyl/acetate grown resting cells of E1 degraded congeners up to octachlorobiphenyl. The degradative patterns for E2 and E3 were assessed using gas chromatographic techniques. E2 was found to be markedly inferior to E1, degrading only the mono-, di-, and tri-chlorobiphenyl tested. Pseudomonas putida strain E3 could not degrade any PCB congener. Mutations in both E2 and E3 that enabled them to utilize more highly chlorinated congeners of PCBs were obtained in nutritionally depleted environments. Such mutants could not be obtained by direct selection using minimal media and appear to be [open quotes]Cairnsian[close quotes] mutations. The Pseudomonas sp. strain E1 was tested in 15 prior or current National Priority List soil microcosms to assess its biodegradative ability in situ. E1 was able to completely degrade the 2,3,4,2[prime],3[prime],4[prime]-2,4,5,2[prime],4[prime],5[prime]-hexachlorobiphenyl congener in seven of the microcosms within two months as well.

  8. Model based evaluation of a contaminant plume development under aerobic and anaerobic conditions in 2D bench-scale tank experiments.

    PubMed

    Ballarini, E; Beyer, C; Bauer, R D; Griebler, C; Bauer, S

    2014-06-01

    The influence of transverse mixing on competitive aerobic and anaerobic biodegradation of a hydrocarbon plume was investigated using a two-dimensional, bench-scale flow-through laboratory tank experiment. In the first part of the experiment aerobic degradation of increasing toluene concentrations was carried out by the aerobic strain Pseudomonas putida F1. Successively, ethylbenzene (injected as a mixture of unlabeled and fully deuterium-labeled isotopologues) substituted toluene; nitrate was added as additional electron acceptor and the anaerobic denitrifying strain Aromatoleum aromaticum EbN1 was inoculated to study competitive degradation under aerobic /anaerobic conditions. The spatial distribution of anaerobic degradation was resolved by measurements of compound-specific stable isotope fractionation induced by the anaerobic strain as well as compound concentrations. A fully transient numerical reactive transport model was employed and calibrated using measurements of electron donors, acceptors and isotope fractionation. The aerobic phases of the experiment were successfully reproduced using a double Monod kinetic growth model and assuming an initial homogeneous distribution of P. putida F1. Investigation of the competitive degradation phase shows that the observed isotopic pattern cannot be explained by transverse mixing driven biodegradation only, but also depends on the inoculation process of the anaerobic strain. Transient concentrations of electron acceptors and donors are well reproduced by the model, showing its ability to simulate transient competitive biodegradation. PMID:24122285

  9. Poplar lignin decomposition by gram-negative aerobic bacteria

    SciTech Connect

    Odier, E.; Janin, G.; Monties, B.

    1981-02-01

    Eleven gram-negative aerobic bacteria (Pseudomonadaceae and Neisseriaceae) out of 122 soil isolates were selected for their ability to assimilate poplar dioxane lignin without a cosubstrate. Dioxane lignin and milled wood lignin degradation rates ranged between 20 and 40% of initial content after 7 days in mineral medium, as determined by a loss of absorbance at 280 nm; 10 strains could degrade in situ lignin, as evidenced by the decrease of the acetyl bromide lignin content of microtome wood sections. No degradation of wood polysaccharides was detected. Lignin biodegradation by Pseudomonas 106 was confirmed by 14CO2 release from labeled poplar wood, although in lower yields compared with results obtained through chemical analysis based on acetyl bromide residual lignin determination. (Refs. 31).

  10. Characterization of pure cultures isolated from sulfamethoxazole-acclimated activated sludge with respect to taxonomic identification and sulfamethoxazole biodegradation potential

    PubMed Central

    2013-01-01

    Background Sulfamethoxazole (SMX, sulfonamide antibiotic) biodegradation by activated sludge communities (ASC) is still only partly understood. The present work is focusing on nine different bacteria species capable of SMX biodegradation that were isolated from SMX-acclimated ASC. Results Initially 110 pure cultures, isolated from activated sludge, were screened by UV-absorbance measurements (UV-AM) for their SMX biodegradation potential. Identification via almost complete 16S rRNA gene sequencing revealed five Pseudomonas spp., one Brevundimonas sp., one Variovorax sp. and two Microbacterium spp.. Thus seven species belonged to the phylum Proteobacteria and two to Actinobacteria. These cultures were subsequently incubated in media containing 10 mg L-1 SMX and different concentrations of carbon (sodium-acetate) and nitrogen (ammonium-nitrate). Different biodegradation patterns were revealed with respect to media composition and bacterial species. Biodegradation, validated by LC-UV measurements to verify UV-AM, occurred very fast with 2.5 mg L-1 d-1 SMX being biodegraded in all pure cultures in, for UV-AM modified, R2A-UV medium under aerobic conditions and room temperature. However, reduced and different biodegradation rates were observed for setups with SMX provided as co-substrate together with a carbon/nitrogen source at a ratio of DOC:N – 33:1 with rates ranging from 1.25 to 2.5 mg L-1 d-1. Conclusions Media containing only SMX as carbon and nitrogen source proved the organisms’ ability to use SMX as sole nutrient source where biodegradation rates decreased to 1.0 – 1.7 mg L-1 d-1. The different taxonomically identified species showed specific biodegradation rates and behaviours at various nutrient conditions. Readily degradable energy sources seem to be crucial for efficient SMX biodegradation. PMID:24289789

  11. FOSSIL FUEL BIODEGRADATION: LABORATORY STUDIES

    EPA Science Inventory

    Natural processes of biodegradation, that return carbon from its various organic forms to the inorganic state, are increasingly screened for bioremediation applications. ariety of microbial systems capable of degrading synthetic organic chemicals, from pesticides to polychlorinat...

  12. Phenanthrene Biodegradation in Freshwater Environments

    PubMed Central

    Sherrill, T. W.; Sayler, G. S.

    1980-01-01

    Phenanthrene, a low-molecular-weight polycyclic aromatic hydrocarbon, was incubated with water samples from various reservoir systems in Tennessee to evaluate the potential for significant polycyclic aromatic hydrocarbon degradation by the indigenous microbial populations. Biodegradation was assessed by comparison of total polycyclic aromatic hydrocarbon substrate recovery in degradation flasks relative to sterile control flasks. During 1977 field studies, the mean phenanthrene biodegradation was approximately 80% after a 4-week incubation. Within a given habitat, 45% of the total variability in phenanthrene biodegradation was attributable to the physical, chemical, and microbiological site characteristics examined. Polycyclic aromatic hydrocarbon degradation was directly related to the historical environmental pollution of the sampling sites examined, the length of biodegradation assessment, temperature, and the molecular size of the polycyclic aromatic hydrocarbon substrate. PMID:16345487

  13. THERMOPHILIC ANAEROBIC BIODEGRADATION OF PHENOLICS

    EPA Science Inventory

    The report gives results of a series of anaerobic microbial acclimation and treatment performance tests with synthetic phenolic substrates. The research is a feasibility level assessment of substituting anaerobic biodegradation of phenolics for solvent extraction. The tests showe...

  14. Biodegradation at Dynamic Plume Fringes: Mixing Versus Reaction Control

    NASA Astrophysics Data System (ADS)

    Cirpka, O. A.; Eckert, D.; Griebler, C.; Haberer, C.; Kürzinger, P.; Bauer, R.; Mellage, A.

    2014-12-01

    Biodegradation of continuously emitted plumes is known to be most pronounced at the plume fringe, where mixing of contaminated water and ambient groundwater, containing dissolved electron acceptors, stimulates microbial activity. Under steady-state conditions, physical mixing of contaminant and electron acceptor by transverse dispersion was shown to be the major bottleneck for biodegradation, with plume lengths scaling inversely with the bulk transverse dispersivity in quasi two-dimensional settings. Under these conditions, the presence of suitable microbes is essential but the biokinetic parameters do not play an important role. When the location of the plume shifts (caused, e.g., by a fluctuating groundwater table), however, the bacteria are no more situated at the plume fringe and biomass growth, decay, activation and deactivation determine the time lag until the fringe-controlled steady state is approached again. During this time lag, degradation is incomplete. The objective of the presented study was to analyze to which extent flow and transport dynamics diminish effectiveness of fringe-controlled biodegradation and which microbial processes and related biokinetic parameters determine the system response in overall degradation to hydraulic fluctuations. We performed experiments in quasi-two-dimensional flow through microcosms on aerobic toluene degradation by Pseudomonas putida F1. Plume dynamics were simulated by vertical alteration of the toluene plume position and experimental results were analyzed by reactive-transport modeling. We found that, even after disappearance of the toluene plume for two weeks, the majority of microorganisms stayed attached to the sediment and regained their full biodegradation potential within two days after reappearance of the toluene plume. Our results underline that besides microbial growth and maintenance (often subsumed as "biomass decay") microbial dormancy (that is, change into a metabolically inactive state) and

  15. Biodegradability of pentachlorophenol in the environment: A literature review

    SciTech Connect

    Nakles, D. )

    1993-04-01

    Pentachlorophenol has been widely used as a wood preserving agent for over 50 years to treat millions of electrical utility poles and crossarms. Treatment of poles with pentachlorophenol has in some cases resulted in contamination of soils, groundwater, and surface water. Environmental releases are a concern because of the potential toxicity of pentachlorophenol and its stringent regulation. Microbiological degradation of pentachlorophenol in environmental media has been demonstrated in numerous cases. The potential for pentachlorophenol to be biologically degraded is of interest to the electrical utility industry for two reasons. First, it is a factor in understanding the probable fate of pentachlorophenol where it has been released into the environment, and second, its biodegradability can potentially result in effective and economical treatment strategies for soils, water, and subsurface environments. The objective of this literature review is to collect a baseline of information on the biodegradability of pentachlorophenol in soils, surface water, and groundwater for the electric utility industry. The focus of the electric utility industry's interest in the environmental management and control of pentachlorophenol is primarily in the management of environmental media, particularly soils, that may have become incidentally contaminated with pentachlorophenol in association with the treatment, storage, or use of utility poles and crossarms. The review of the literature has found that [open quotes]unassisted[close quotes] biodegradation of pentachlorophenol in aquatic, soil, and subsurface environments may occur, presumably if there is an acclimated microbial population of sufficient density. Aerobic conditions appear to be most conducive to biodegradation in these cases. Several studies have shown that with an acclimated, mixed culture and conventional wastewater treatment approaches, pentachlorophenol can be effectively treated in water.

  16. Temperature effect on tert-butyl alcohol (TBA) biodegradation kinetics in hyporheic zone soils

    PubMed Central

    Greenwood, Mark H; Sims, Ronald C; McLean, Joan E; Doucette, William J

    2007-01-01

    Background Remediation of tert-butyl alcohol (TBA) in subsurface waters should be taken into consideration at reformulated gasoline contaminated sites since it is a biodegradation intermediate of methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-butyl formate (TBF). The effect of temperature on TBA biodegradation has not been not been published in the literature. Methods Biodegradation of [U 14C] TBA was determined using hyporheic zone soil microcosms. Results First order mineralization rate constants of TBA at 5°C, 15°C and 25°C were 7.84 ± 0.14 × 10-3, 9.07 ± 0.09 × 10-3, and 15.3 ± 0.3 × 10-3 days-1, respectively (or 2.86 ± 0.05, 3.31 ± 0.03, 5.60 ± 0.14 years-1, respectively). Temperature had a statistically significant effect on the mineralization rates and was modelled using the Arrhenius equation with frequency factor (A) and activation energy (Ea) of 154 day-1 and 23,006 mol/J, respectively. Conclusion Results of this study are the first to determine mineralization rates of TBA for different temperatures. The kinetic rates determined in this study can be used in groundwater fate and transport modelling of TBA at the Ronan, MT site and provide an estimate for TBA removal at other similar shallow aquifer sites and hyporheic zones as a function of seasonal change in temperature. PMID:17877835

  17. Biodegradability and aquatic toxicity of quaternary ammonium-based gemini surfactants: Effect of the spacer on their ecological properties.

    PubMed

    Garcia, M Teresa; Kaczerewska, Olga; Ribosa, Isabel; Brycki, Bogumił; Materna, Paulina; Drgas, Małgorzata

    2016-07-01

    Aerobic biodegradability and aquatic toxicity of five types of quaternary ammonium-based gemini surfactants have been examined. The effect of the spacer structure and the head group polarity on the ecological properties of a series of dimeric dodecyl ammonium surfactants has been investigated. Standard tests for ready biodegradability assessment (OECD 310) were conducted for C12 alkyl chain gemini surfactants containing oxygen, nitrogen or a benzene ring in the spacer linkage and/or a hydroxyethyl group attached to the nitrogen atom of the head groups. According to the results obtained, the gemini surfactants examined cannot be considered as readily biodegradable compounds. The negligible biotransformation of the gemini surfactants under the standard biodegradation test conditions was found to be due to their toxic effects on the microbial population responsible for aerobic biodegradation. Aquatic toxicity of gemini surfactants was evaluated against Daphnia magna. The acute toxicity values to Daphnia magna, IC50 at 48 h exposure, ranged from 0.6 to 1 mg/L. On the basis of these values, the gemini surfactants tested should be classified as toxic or very toxic to the aquatic environment. However, the dimeric quaternary ammonium-based surfactants examined result to be less toxic than their corresponding monomeric analogs. Nevertheless the aquatic toxicity of these gemini surfactants can be reduced by increasing the molecule hydrophilicity by adding a heteroatom to the spacer or a hydroxyethyl group to the polar head groups. PMID:27045632

  18. Biodegradation of partially hydrolyzed polyacrylamide by bacteria isolated from production water after polymer flooding in an oil field.

    PubMed

    Bao, Mutai; Chen, Qingguo; Li, Yiming; Jiang, Guancheng

    2010-12-15

    Partially hydrolyzed polyacrylamide (HPAM) in production water after polymer flooding in oil filed causes environmental problems, such as increases the difficulty in oil-water separation, degrades naturally to produce toxic acrylamide and endanger local ecosystem. Biodegradation of HPAM may be an efficient way to solve these problems. The biodegradability of HPAM in an aerobic environment was studied. Two HPAM-degrading bacterial strains, named PM-2 and PM-3, were isolated from the produced water of polymer flooding. They were subsequently identified as Bacillus cereus and Bacillus sp., respectively. The utilization of HPAM by the two strains was explored. The amide group of HPAM could serve as a nitrogen source for the two microorganisms, the carbon backbone of these polymers could be partly utilized by microorganisms. The HPAM samples before and after bacterial biodegradation were analyzed by the infrared spectrum, high performance liquid chromatography and scanning electronic microscope. The results indicated that the amide group of HPAM in the biodegradation products had been converted to a carboxyl group, and no acrylamide monomer was found. The HPAM carbon backbone was metabolized by the bacteria during the course of its growth. Further more, the hypothesis about the biodegradation of HPAM in aerobic bacterial culture is proposed. PMID:20813455

  19. The Transition from Aerobic to Anaerobic Metabolism.

    ERIC Educational Resources Information Center

    Skinner, James S.; McLellan, Thomas H.

    1980-01-01

    The transition from aerobic to anaerobic metabolism is discussed. More research is needed on different kinds of athletes and athletic activities and how they may affect aerobic and anaerobic metabolisms. (CJ)

  20. Biodegradation of atrazine by Rhodococcus sp. BCH2 to N-isopropylammelide with subsequent assessment of toxicity of biodegraded metabolites.

    PubMed

    Kolekar, Parag D; Phugare, Swapnil S; Jadhav, Jyoti P

    2014-02-01

    Atrazine is a persistent organic pollutant in the environment which affects not only terrestrial and aquatic biota but also human health. Since its removal from the environment is needed, atrazine biodegradation is achieved in the present study using the bacterium Rhodococcus sp. BCH2 isolated from soil, long-term treated with atrazine. The bacterium was capable of degrading about 75 % atrazine in liquid medium having pH 7 under aerobic and dark condition within 7 days. The degradation ability of the bacterium at various temperatures (20-60 °C), pH (range 3-11), carbon (glucose, fructose, sucrose, starch, lactose, and maltose), and nitrogen (ammonium molybdate, sodium nitrate, potassium nitrate, and urea) sources were studied for triumph optimum atrazine degradation. The results indicate that atrazine degradation at higher concentrations (100 ppm) was pH and temperature dependent. However, glucose and potassium nitrate were optimum carbon and nitrogen source, respectively. Atrazine biodegradation analysis was carried out by using high-performance thin-layer chromatography (HPTLC), Fourier transform infrared spectroscopy (FTIR), and liquid chromatography quadrupole time-of-flight (LC/Q-TOF-MS) techniques. LC/Q-TOF-MS analysis revealed formation of various intermediate metabolites including hydroxyatrazine, N-isopropylammelide, deisopropylhydroxyatrazine, deethylatrazine, deisopropylatrazine, and deisopropyldeethylatrazine which was helpful to propose biochemical degradation pathway of atrazine. Furthermore, the toxicological studies of atrazine and its biodegraded metabolites were executed on earthworm Eisenia foetida as a model organism with respect to enzymatic (SOD and Catalase) antioxidant defense mechanism and lipid peroxidation studies. These results suggest innocuous degradation of atrazine by Rhodococcus sp. BCH2 in nontoxic form. Therefore the Rhodococcus sp.BCH2 could prove a valuable source for the eco-friendly biodegradation of atrazine pesticide. PMID

  1. [Application of Micro-aerobic Hydrolysis Acidification in the Pretreatment of Petrochemical Wastewater].

    PubMed

    Zhu, Chen; Wu, Chang-yong; Zhou, Yue-xi; Fu, Xiao-yong; Chen, Xue-min; Qiu, Yan-bo; Wu, Xiao-feng

    2015-10-01

    Micro-aerobic hydrolysis acidification technology was applied in the reconstruction of ananaerobic hydrolysis acidification tank in a north petrochemical wastewater treatment plant. After put into operation, the monitoring results showed that the average removal rate of COD was 11.7% when influent COD was 490.3-673.2 mg x L(-1), hydraulic retention time (HRT) was 24 and the dissolved oxygen (DO) was 0.2-0.35 mg x L(-1). In addition, the BOD5/COD value was increased by 12.4%, the UV254 removal rate reached 11.2%, and the VFA concentration was increased by 23.0%. The relative molecular weight distribution (MWD) results showed that the small molecule organic matter (< 1 x 10(3)) percentage was increased from 59.5% to 82.1% and the high molecular organic matter ( > 100 x 10(3)) percentage was decreased from 31.8% to 14.0% after micro-aerobic hydrolysis acidification. The aerobic biodegradation batch test showed that the degradation of petrochemical wastewater was significantly improved by the pretreatment of micro-aerobic hydrolysis acidification. The COD of influent can be degraded to 102.2 mg x L(-1) by 48h aerobic treatment while the micro-aerobic hydrolysis acidification effluent COD can be degraded to 71.5 mg x L(-1) on the same condition. The effluent sulfate concentration of micro-aerobic hydrolysis acidification tank [(930.7 ± 60.1) mg x L(-1)] was higher than that of the influent [(854.3 ± 41.5) mg x L(-1)], indicating that sulfate reducing bacteria (SRB) was inhibited. The toxic and malodorous gases generation was reduced with the improvement of environment. PMID:26841606

  2. Comparison of Leachate Quality from Aerobic and Anaerobic Municipal Solid Waste Bioreactors

    NASA Astrophysics Data System (ADS)

    Borglin, S. E.; Hazen, T. C.; Oldenburg, C. M.

    2002-12-01

    Municipal solid waste landfills are becoming a drain on the resources of local municipalities as the requirements for stabilization and containment become increasingly stringent. Current regulations limit the moisture in the landfill to minimize leachate production and lower the potential for release of leachate to the environment. Recent research has shown that addition and recycling of moisture in the waste optimizes the biodegradation of stabilization and also provides a means for leachate treatment. This study compares the characteristics of leachate produced from aerobic and anaerobic laboratory bioreactors, and leachate collected from a full-scale anaerobic bioreactor. The laboratory reactors consisted of 200-liter tanks filled with fresh waste materials with the following conditions: (a) aerobic (air injection with leachate recirculation), (b) anaerobic (leachate recirculation). The leachate from the reactors was monitored for metals, nutrients, organic carbon, and microbiological activity for up to 500 days. Leachate from the aerobic tank had significantly lower concentrations of all potential contaminants, both organic and metal, after only a few weeks of operation. Metals leaching was low throughout the test period for the aerobic tanks, and decreased over time for the anaerobic tanks. Organic carbon as measured by BOD, COD, TOC, and COD were an order of magnitude higher in the leachate from the anaerobic system. Microbiological assessment by lipid analysis, enzyme activity assays, and cell counts showed high biomass and diversity in both the aerobic and anaerobic bioreactors, with higher activity in the anaerobic leachate. Results from the full-scale anaerobic bioreactor were not significantly different from those of the laboratory anaerobic bioreactor. The reduction in noxious odors was a significant advantage of the aerobic system. These results suggest that aerobic management of landfills could reduce or eliminate the need for leachate treatment

  3. [Degradation Characteristics of Three Aniline Compounds in Simulated Aerobic Sewage Treat System].

    PubMed

    Gu, Wen; Zhou, Lin-jun; Liu, Ji-ning; Chen, Guo-song; Shi, Li-li; Xu, Yan-hua

    2016-01-15

    The removal rates of 4-nitroaniline, 4-isopropyl aniline and 2-chloro-4-nitroaniline under different hydraulic retention time (HRT) were tested by employing a simulation method of aerobic biochemical sewage treatment technology in this study. The results showed that when HRT was 6 h, 12 h, and 24 h, the removal rates of dissolved organic carbon (DOC) were 70.2%, 80.3% and 88.3%, the removal rates of 4-nitroaniline were 48%, 64.7% and 75%; and the removal rates of 4-isopropyl aniline were 66%, 76% and 91%, respectively. It was concluded that increasing HRT could promote the removal rates of DOC and aniline chemicals. In contrast, 2-chloro-4-nitroaniline was difficult to be removed. The removal rates were less than 20% under all tested conditions. The kinetics analysis showed that the biodegradation of 4-nitroaniline, 4-isopropyl aniline and 2-chloro-4-nitroaniline in aerobic activated sewage (3 g x L(-1)) accorded with the first order kinetics and the regression coefficients were > 0.95. The half-life time of biodegradation was 6.01 h, 16.16 h, 123.75 h, respectively. In general, functional groups such as isopropyl had a positive effect on the biodegradation of aniline chemicals, whereas substituents such as nitro group and chlorine atom had an inhibitory effect. PMID:27078963

  4. "Aerobic" Writing: A Writing Practice Model.

    ERIC Educational Resources Information Center

    Crisp, Sally Chandler

    "Aerobic writing" is a writing center strategy designed to keep students in writing "shape." Like aerobic exercise, aerobic writing is sustained for a certain length of time and done on a regular basis at prescribed time intervals. The program requires students to write at least two times a week for approximately an hour each time. Students write,…

  5. Arthritis and Aerobic Exercise: A Review.

    ERIC Educational Resources Information Center

    Ike, Robert W.; And Others

    1989-01-01

    Arthritic patients who regularly do aerobic exercise make significant gains in aerobic and functional status, and in subjective areas like pain tolerance and mood. Still, they are often advised to curtail physical activity. Guidelines are presented for physicians prescribing aerobic exercise. An exercise tolerance test is recommended. (SM)

  6. Ecotoxicity by the biodegradation of alkylphenol polyethoxylates depends on the effect of trace elements.

    PubMed

    Hotta, Yudai; Hosoda, Akifumi; Sano, Fumihiko; Wakayama, Manabu; Niwa, Katsuki; Yoshikawa, Hiromichi; Tamura, Hiroto

    2010-01-27

    The bacteria Sphingomonas sp. strain BSN22, isolated from bean fields, degraded octylphenol polyethoxylates (OPEO(n)) to octylphenol (OP) under aerobic conditions. This biodegradation mechanism proceeded by the following two-step degradation process: (1) degradation of OPEO(n) to octylphenol triethoxylate (OPEO(3)), (2) degradation from OPEO(3) to OP via octylphenoxy acetic acid (OPEC(1)). The chemical structure of OPEC(1) was confirmed by analysis using (18)O-labeled water. Quantitative studies revealed that magnesium (Mg(2+)) and calcium (Ca(2+)) ions were essential for the biodegradation of OPEO(n). Furthermore, the rate of biodegradation was especially accelerated by ferric ions (Fe(3+)), and the accumulated amounts of endocrine active chemicals, such as OP, OPEO(1), and OPEC(1), significantly increased to the concentration of 22.8, 221.7, and 961.1 microM in the presence of 37.0 microM Fe(3+), respectively. This suggests that environmental elements significantly influence the resultant ecotoxicity as well as the rate of their biodegradation in the environment. This study on the mechanism of OPEO(n) biodegradation may play an important role in understanding and managing environmental safety, including drinking water safety. PMID:20025273

  7. Enantiomeric fractionation as a tool for quantitative assessment of biodegradation: The case of metoprolol.

    PubMed

    Souchier, Marine; Benali-Raclot, Dalel; Casellas, Claude; Ingrand, Valérie; Chiron, Serge

    2016-05-15

    An efficient chiral liquid chromatography high resolution mass spectrometry method has been developed for the determination of metoprolol (MTP) and three of its major metabolites, namely O-desmethylmetoprolol (O-DMTP), α-hydroxymetoprolol (α-HMTP) and metoprolol acid (MTPA) in wastewater treatment plant (WWTP) influents and effluents. The optimized analytical method has been validated with good quality parameters including resolution >1.3 and method quantification limits down to the ng/L range except for MTPA. On the basis of this newly developed analytical method, the stereochemistry of MTP and its metabolites was studied over time in effluent/sediment biotic and sterile microcosms under dark and light conditions and in influents and effluents of 5 different WWTPs. MTP stereoselective degradation was exclusively observed under biotic conditions, confirming the specificity of enantiomeric fraction variations to biodegradation processes. MTP was always biotransformed into MTPA with a (S)-enantiomer enrichment. The results of enantiomeric enrichment pointed the way for a quantitative assessment of in situ biodegradation processes due to a good fit (R(2) > 0.98) of the aerobic MTP biodegradation to the Rayleigh dependency in all the biotic microcosms and in WWTPs because both MTP enantiomers followed the same biodegradation kinetic profiles. These results demonstrate that enantiomeric fractionation constitutes a very interesting quantitative indicator of MTP biodegradation in WWTPs and probably in the environment. PMID:26978718

  8. Biodegradation of radioactive animals

    SciTech Connect

    Party, N.; Party, E.; Wilkerson, A.

    1995-06-01

    The two most common disposal alternatives for animals contaminated with radioactive materials are incineration and burial. For most of the country burial has entailed shipping the carcasses to a commercial disposal facility at Barnwell, South Carolina, where it was landfilled along with other solid radioactive waste. Unfortunately, since 30 June 1994, this facility accepts waste generated by the states of the Southeast Compact only. Therefore, burial is no longer an option for most of the country`s generators and incineration is an option only for those institutions which have, or have access to, an incinerator that is permitted to burn radioactive materials and that accepts animal carcasses with de minimis levels of radioactive contaminants. Many institutions, especially those in congested urban areas where the public does not support incineration, do not have viable outlets for radioactive animal carcasses. Interim, on-site storage poses problems of its own. Biodegradation of animal carcasses with dermestid beetles is an inexpensive approach to this waste management problem. 7 refs., 3 figs., 1 tab.

  9. Biodegradation of polyethoxylated nonylphenols.

    PubMed

    Ruiz, Yassellis; Medina, Luis; Borusiak, Margarita; Ramos, Nairalith; Pinto, Gilberto; Valbuena, Oscar

    2013-01-01

    Polyethoxylated nonylphenols, with different ethoxylation degrees (NPEO x ), are incorporated into many commercial and industrial products such as detergents, domestic disinfectants, emulsifiers, cosmetics, and pesticides. However, the toxic effects exerted by their degradation products, which are persistent in natural environments, have been demonstrated in several animal and invertebrate aquatic species. Therefore, it seems appropriate to look for indigenous bacteria capable of degrading native NPEO x and its derivatives. In this paper, the isolation of five bacterial strains, capable of using NPEO 15 , as unique carbon source, is described. The most efficient NPEO 15 degrader bacterial strains were identified as Pseudomonas fluorescens (strain Yas2) and Klebsiella pneumoniae (strain Yas1). Maximal growth rates were reached at pH 8, 27°C in a 5% NPEO 15 medium. The NPEO 15 degradation extension, followed by viscometry assays, reached 65% after 54.5 h and 134 h incubation times, while the COD values decreased by 95% and 85% after 24 h for the Yas1 and Yas2 systems, respectively. The BOD was reduced by 99% and 99.9% levels in 24 h and 48 h incubations. The viscosity data indicated that the NPEO 15 biodegradation by Yas2 follows first-order kinetics. Kinetic rate constant (k) and half life time (τ) for this biotransformation were estimated to be 0.0072 h(-1) and 96.3 h, respectively. PMID:23936727

  10. Biodegradation of Polyethoxylated Nonylphenols

    PubMed Central

    Ruiz, Yassellis; Medina, Luis; Borusiak, Margarita; Ramos, Nairalith; Pinto, Gilberto; Valbuena, Oscar

    2013-01-01

    Polyethoxylated nonylphenols, with different ethoxylation degrees (NPEOx), are incorporated into many commercial and industrial products such as detergents, domestic disinfectants, emulsifiers, cosmetics, and pesticides. However, the toxic effects exerted by their degradation products, which are persistent in natural environments, have been demonstrated in several animal and invertebrate aquatic species. Therefore, it seems appropriate to look for indigenous bacteria capable of degrading native NPEOx and its derivatives. In this paper, the isolation of five bacterial strains, capable of using NPEO15, as unique carbon source, is described. The most efficient NPEO15 degrader bacterial strains were identified as Pseudomonas fluorescens (strain Yas2) and Klebsiella pneumoniae (strain Yas1). Maximal growth rates were reached at pH 8, 27°C in a 5% NPEO15 medium. The NPEO15 degradation extension, followed by viscometry assays, reached 65% after 54.5 h and 134 h incubation times, while the COD values decreased by 95% and 85% after 24 h for the Yas1 and Yas2 systems, respectively. The BOD was reduced by 99% and 99.9% levels in 24 h and 48 h incubations. The viscosity data indicated that the NPEO15 biodegradation by Yas2 follows first-order kinetics. Kinetic rate constant (k) and half life time (τ) for this biotransformation were estimated to be 0.0072 h−1 and 96.3 h, respectively. PMID:23936727

  11. Fate of estrogen conjugate 17α-estradiol-3-sulfate in dairy wastewater: comparison of aerobic and anaerobic degradation and metabolite formation.

    PubMed

    Zheng, Wei; Zou, Yonghong; Li, Xiaolin; Machesky, Michael L

    2013-08-15

    Irrigation with concentrated animal feeding operation (CAFO) wastewater on croplands has been identified as a major source discharging steroid hormones into the environment. To assess the potential risks on this irrigation practice, the degradation kinetics and mechanisms of 17α-estradiol-3-sulfate were systematically investigated in aqueous solutions blended with dairy wastewater. Dissipation of the conjugated estrogen was dominated by biodegradation under both aerobic and anaerobic conditions. The half-lives for the biodegradation of 17α-estradiol-3-sulfate under aerobic and anaerobic conditions from 15 to 45°C varied from 1.70 to 415 d and 22.5 to 724 d, respectively. Under the same incubation conditions, anaerobic degradation rates of 17α-estradiol-3-sulfate were significantly less than aerobic degradation rates, suggesting that this hormone contaminant may accumulate in anaerobic or anoxic environments. Three degradation products were characterized under both aerobic and anaerobic conditions at 25°C, with estrone-3-sulfate and 17α-estradiol identified as primary metabolites and estrone identified as a secondary metabolite. However, the major degradation mechanisms under aerobic and anaerobic conditions were distinctly different. For aerobic degradation, oxidation at position C17 of the 17α-estradiol-3-sulfate ring was a major degradation mechanism. In contrast, deconjugation of the 17α-estradiol-3-sulfate thio-ester bond at position C3 was a major process initiating degradation under anaerobic conditions. PMID:23708453

  12. Process Improvements: Aerobic Food Waste Composting at ISF Academy

    NASA Astrophysics Data System (ADS)

    Lau, Y. K.

    2015-12-01

    ISF Academy, a school with 1500 students in Hong Kong, installed an aerobic food waste composting system in November of 2013. The system has been operational for over seven months; we will be making improvements to the system to ensure the continued operational viability and quality of the compost. As a school we are committed to reducing our carbon footprint and the amount of waste we send to the local landfill. Over an academic year we produce approximately 27 metric tons of food waste. Our system processes the food waste to compost in 14 days and the compost is used by our primary school students in a organic farming project.There are two areas of improvement: a) if the composting system becomes anaerobic, there is an odor problem that is noticed by the school community; we will be testing the use of a bio-filter to eliminate the odor problem and, b) we will be working with an equipment vendor from Australia to install an improved grease trap system. The grease and oil that is collected will be sold to a local company here in Hong Kong that processes used cooking oil for making biofuels. This system will include a two stage filtration system and a heated vessel for separating the oil from the waste water.The third project will be to evaluate biodegradable cutlery for the compositing in the system. Currently, we use a significant quantity of non-biodegradable cutlery that is then thrown away after one use. Several local HK companies are selling biodegradable cutlery, but we need to evaluate the different products to determine which ones will work with our composting system. The food waste composting project at ISF Academy demonstrates the commitment of the school community to a greener environment for HK, the above listed projects will improve the operation of the system.

  13. Injectable and biodegradable hydrogels: gelation, biodegradation and biomedical applications.

    PubMed

    Li, Yulin; Rodrigues, João; Tomás, Helena

    2012-03-21

    Injectable hydrogels with biodegradability have in situ formability which in vitro/in vivo allows an effective and homogeneous encapsulation of drugs/cells, and convenient in vivo surgical operation in a minimally invasive way, causing smaller scar size and less pain for patients. Therefore, they have found a variety of biomedical applications, such as drug delivery, cell encapsulation, and tissue engineering. This critical review systematically summarizes the recent progresses on biodegradable and injectable hydrogels fabricated from natural polymers (chitosan, hyaluronic acid, alginates, gelatin, heparin, chondroitin sulfate, etc.) and biodegradable synthetic polymers (polypeptides, polyesters, polyphosphazenes, etc.). The review includes the novel naturally based hydrogels with high potential for biomedical applications developed in the past five years which integrate the excellent biocompatibility of natural polymers/synthetic polypeptides with structural controllability via chemical modification. The gelation and biodegradation which are two key factors to affect the cell fate or drug delivery are highlighted. A brief outlook on the future of injectable and biodegradable hydrogels is also presented (326 references). PMID:22116474

  14. Use of Advanced Oxidation and Aerobic Degradation for Remediation of Various Hydrocarbon Contaminates

    SciTech Connect

    Paul Fallgren

    2009-03-06

    Western Research Institute in conjunction with Sierra West Consultants, Inc., Tetra Tech, Inc., and the U.S. Department of Energy conducted laboratory and field studies to test different approaches to enhance degradation of hydrocarbons and associated contaminants. WRI in conjunction with Sierra West Consultants, Inc., conducted a laboratory and field study for using ozone to treat a site contaminated with MTBE and other hydrocarbons. Results from this study demonstrate that a TOD test can be used to resolve the O{sub 3} dosage problem by establishing a site-specific benchmark dosage for field ozone applications. The follow-up testing of the laboratory samples provided indications that intrinsic biodegradation could be stimulated by adding oxygen. Laboratory studies also suggests that O3 dosage in the full-scale field implementation could be dialed lower than stoichiometrically designed to eliminate the formation of Cr(VI). WRI conducted a study involving a series of different ISCO oxidant applications to diesel-contaminated soil and determined the effects on enhancing biodegradation to degrade the residual hydrocarbons. Soils treated with permanganate followed by nutrients and with persulfate followed by nutrients resulted in the largest decrease in TPH. The possible intermediates and conditions formed from NOM and TPH oxidation by permanganate and activated persulfate favors microbial TPH degrading activity. A 'passive-oxidation' method using microbial fuel cell (MFC) technology was conducted by WRI in conjunction with Tetra Tech, Inc., to degrade MTBE in groundwater. These experiments have demonstrated that a working MFC (i.e., one generating power) could be established in the laboratory using contaminated site water or buffered media inoculated with site water and spiked with MTBE, benzene, or toluene. Electrochemical methods were studied by WRI with goal of utilizing low voltage and amperage electrical sources for 'geo-oxidation' of organic contaminants. The

  15. Biodegradation Kinetics of 1,4-Dioxane in Chlorinated Solvent Mixtures.

    PubMed

    Zhang, Shu; Gedalanga, Phillip B; Mahendra, Shaily

    2016-09-01

    This study investigated the impacts of individual chlorinated solvents and their mixtures on aerobic 1,4-dioxane biodegradation by Pseudonocardia dioxanivorans CB1190. The established association of these co-occurring compounds suggests important considerations for their respective biodegradation processes. Our kinetics and mechanistic studies demonstrated that individual solvents inhibited biodegradation of 1,4-dioxane in the following order: 1,1-dichloroethene (1,1-DCE) > cis-1,2-diochloroethene (cDCE) > trichloroethene (TCE) > 1,1,1-trichloroethane (TCA). The presence of 5 mg L(-1) 1,1-DCE completely inhibited 1,4-dioxane biodegradation. Subsequently, we determined that 1,1-DCE was the strongest inhibitor of 1,4-dioxane biodegradation by bacterial pure cultures exposed to chlorinated solvent mixtures as well as in environmental samples collected from a site contaminated with chlorinated solvents and 1,4-dioxane. Inhibition of 1,4-dioxane biodegradation rates by chlorinated solvents was attributed to delayed ATP production and down-regulation of both 1,4-dioxane monooxygenase (dxmB) and aldehyde dehydrogenase (aldH) genes. Moreover, increasing concentrations of 1,1-DCE and cis-1,2-DCE to 50 mg L(-1) respectively increased 5.0-fold and 3.5-fold the expression of the uspA gene encoding a universal stress protein. In situ natural attenuation or enhanced biodegradation of 1,4-dioxane is being considered for contaminated groundwater and industrial wastewater, so these results will have implications for selecting 1,4-dioxane bioremediation strategies at sites where chlorinated solvents are present as co-contaminants. PMID:27486928

  16. {gamma}-aminobutyric acid{sub A} (GABA{sub A}) receptor regulates ERK1/2 phosphorylation in rat hippocampus in high doses of Methyl Tert-Butyl Ether (MTBE)-induced impairment of spatial memory

    SciTech Connect

    Zheng Gang; Zhang Wenbin; Zhang Yun; Chen Yaoming; Liu Mingchao; Yao Ting; Yang Yanxia; Zhao Fang; Li Jingxia; Huang Chuanshu; Luo Wenjing Chen Jingyuan

    2009-04-15

    Experimental and occupational exposure to Methyl Tert-Butyl Ether (MTBE) has been reported to induce neurotoxicological and neurobehavioral effects, such as headache, nausea, dizziness, and disorientation, etc. However, the molecular mechanisms involved in MTBE-induced neurotoxicity are still not well understood. In the present study, we investigated the effects of MTBE on spatial memory and the expression and function of GABA{sub A} receptor in the hippocampus. Our results demonstrated that intraventricular injection of MTBE impaired the performance of the rats in a Morris water maze task, and significantly increased the expression of GABA{sub A} receptor {alpha}1 subunit in the hippocampus. The phosphorylation of ERK1/2 decreased after the MTBE injection. Furthermore, the decreased ability of learning and the reduction of phosphorylated ERK1/2 level of the MTBE-treated rats was partly reversed by bicuculline injected 30 min before the training. These results suggested that MTBE exposure could result in impaired spatial memory. GABA{sub A} receptor may play an important role in the MTBE-induced impairment of learning and memory by regulating the phosphorylation of ERK in the hippocampus.

  17. Effects of the Biodegradation on Biodegradable Polymer Blends and Polypropylene

    NASA Astrophysics Data System (ADS)

    Pereira, R. C. T.; Franchetti, S. M. M.; Agnelli, J. A. M.; Mattoso, L. H. C.

    2008-08-01

    The large use of plastics in the world generates a large amount of waste which persists around 200 years in the environment. To minimize this effect is important to search some new polymer materials: the blends of biodegradable polymers with synthetic polymers. It is a large area that needs an intensive research to investigate the blends properties and its behavior face to the different treatments to aim at the biodegradation. The blends used in this work are: some biodegradable polymers such as: poly(hydroxybutyrate) (PHB) and poly(ɛ-polycaprolactone) (PCL) with a synthetic polymer, polypropylene (PP), in lower concentration. These blends were prepared using an internal mixer (Torque Rheometer), and pressed. These films were submitted to fungus biotreatment. The films analyses will be carried out by Fourier Transform Infrared (FTIR), UV-Vis absorption (UV-Vis), Scanning Electronic Microscopy (SEM), DSC and TGA.

  18. Microbial biosafety of pilot-scale bioreactor treating MTBE and TBA-contaminated drinking water supply

    PubMed Central

    Schmidt, Radomir; Klemme, David A.; Scow, Kate; Hristova, Krassimira

    2012-01-01

    A pilot-scale sand-based fluidized bed bioreactor (FBBR) was utilized to treat both methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) from a contaminated aquifer. To evaluate the potential for re-use of the treated water, we tested for a panel of water quality indicator microorganisms and potential waterborne pathogens including total coliforms, E. coli, Salmonella and Shigella spp., Campylobacter jejuni, Aeromonas hydrophila, Legionella pneumophila, Vibrio cholerae, Yersinia enterocolytica and Mycobacterium avium in both influent and treated waters from the bioreactor. Total bacteria decreased during FBBR treatment. E. coli, Salmonella and Shigella spp., C. jejuni, V. cholerae, Y. enterocolytica and M. avium were not detected in aquifer water or bioreactor treated water samples. For those pathogens detected, including total coliforms, L. pneumophila and A. hydrophila, numbers were usually lower in treated water than influent samples, suggesting removal during treatment. The detection of particular bacterial species reflected their presence or absence in the influent waters. PMID:22321859

  19. Shock tube ignition of ethanol, isobutene and MTBE: Experiments and modeling

    SciTech Connect

    Curran, H.J.; Dunphy, M.P.; Simmie, J.M. . Dept. of Chemistry); Westbrook, C.K.; Pitz, W.J. )

    1991-11-22

    The ignition of ethanol, isobutene and methyl tert-butyl ether (MTBE) has been studied experimentally in a shock tube and computationally with a detailed chemical kinetic model. Experimental results, consisting of ignition delay measurements, were obtained for a range of fuel/oxygen mixtures diluted in Argon, with temperatures varying over a range of 1100--1900 K. The numerical model consisted of a detailed kinetic reaction mechanism with more than 400 elementary reactions, chosen to describe reactions of each fuel and the smaller hydrocarbon and other species produced during their oxidation. The overall agreement between experimental and computed results was excellent, particularly for mixtures with greater than 0.3% fuel. The greatest sensitivity in the computed results was found to falloff parameters in the dissociation reactions of isobutene, ethane, methane, and ethyl and vinyl radicals, to the C{sub 3}H{sub 4} and C{sub 3}H{sub 5} reaction submechanisms in the model, and to the reactions in the H{sub 2}-O{sub 2}-Co submechanism.

  20. Biodegradation of news inks

    SciTech Connect

    Erhan, S.Z.; Bagby, M.O.

    1995-12-01

    Printing ink vehicles that require no petroleum components were prepared by modifying vegetable oil. Physical properties of inks formulated with these vehicles meet or exceed the industry standards for lithographic and letterpress newsprint applications. Elimination of petroleum-based resin and reduced pigment requirements, due to the light vehicle color, provide a competitively priced alternative to petroleum-based inks of equal quality. These ink vehicles, made exclusively from soybean oil, were subjected to biodegradation, and the results were compared with those obtained with commercial vehicles. Results show that they degrade faster and more completely than commercial hybrid (partial) soy or mineral oil based vehicles. Fermentations were allowed to proceed for 5, 12, and 25 days. Both mono-and mixed cultures of microorganisms commonly found in soil were used. In 25 days, commercial mineral oil based vehicles degraded 17-27%, while commercial hybrid soy oil based vehicles degraded 58-68% and our 100% soy oil based vehicles degrade 82-92%. Similar studies were conducted with commercial news inks consisting of soy or mineral oil with petroleum resins along with the four colored pigments and USDA`s 100% soy oil based ink consisting of modified soybean oil and pigment. Results show that pigment slowed the degradation of ink vehicles; however, neither time nor type of pigment played a significant role. Also these inks were degraded by using {open_quotes}Modified Sturm Test{close_quotes} (Organization for Economic Cooperation and Development). In this method, test organisms were obtained from activated sludge, and the extent of degradation was determined by measuring carbon dioxide evolution. In all cases USDA`s ink degraded faster and more completely (for all four colors) than either hybrid soy oil based or petroleum based inks.

  1. Release of biodegradable dissolved organic matter from ancient sedimentary rocks

    NASA Astrophysics Data System (ADS)

    Schillawski, Sarah; Petsch, Steven

    2008-09-01

    Sedimentary rocks contain the largest mass of organic carbon on Earth, yet these reservoirs are not well integrated into modern carbon budgets. Here we describe the release of dissolved organic matter (DOM) from OM-rich sedimentary rocks under simulated weathering conditions. Results from column experiments demonstrate slow, sustained release of DOM from ancient sedimentary rocks under simulated weathering conditions. 1H-NMR analysis of shale-derived DOM reveals a highly aliphatic, carbohydrate-poor material distinct from other natural DOM pools. Shale-derived DOM is rapidly assimilated and biodegraded by aerobic heterotrophic bacteria. Consequently, no compositional signature of shale-derived DOM other than 14C-depletion is likely to persist in rivers or other surface reservoirs. Combined, these efforts show that dissolution provides a mechanism for the conversion of refractory kerogen into labile biomass, linking rock weathering with sedimentary OM oxidation and the delivery of aged OM to rivers and ocean margins.

  2. Initial Transformations in the Biodegradation of Benzothiazoles by Rhodococcus Isolates

    PubMed Central

    De Wever, Helene; Vereecken, Karen; Stolz, Andreas; Verachtert, Hubert

    1998-01-01

    Benzothiazole-2-sulfonate (BTSO3) is one of the side products occurring in 2-mercaptobenzothiazole (MBT) production wastewater. We are the first to isolate an axenic culture capable of BTSO3 degradation. The isolate was identified as a Rhodococcus erythropolis strain and also degraded 2-hydroxybenzothiazole (OBT) and benzothiazole (BT), but not MBT, which was found to inhibit the biodegradation of OBT, BT, and BTSO3. In anaerobic resting cell assays, BTSO3 was transformed into OBT in stoichiometric amounts. Under aerobic conditions, OBT was observed as an intermediate in BT breakdown and an unknown compound transiently accumulated in several assays. This product was identified as a dihydroxybenzothiazole. Benzothiazole degradation pathways seem to converge into OBT, which is then transformed further into the dihydroxy derivative. PMID:9726870

  3. Improved RDX detoxification with starch addition using a novel nitrogen-fixing aerobic microbial consortium from soil contaminated with explosives.

    PubMed

    Khan, Muhammad Imran; Yang, Jihoon; Yoo, Byungun; Park, Joonhong

    2015-04-28

    In this work, we developed and characterized a novel nitrogen-fixing aerobic microbial consortium for the complete detoxification of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). Aerobic RDX biodegradation coupled with microbial growth and nitrogen fixation activity were effectively stimulated by the co-addition of starch and RDX under nitrogen limiting conditions. In the starch-stimulated nitrogen-fixing RDX degradative consortium, the RDX degradation activity was correlated with the xplA and nifH gene copy numbers, suggesting the involvement of nitrogen fixing populations in RDX biodegradation. Formate, nitrite, nitrate, and ammonia were detected as aerobic RDX degradation intermediates without the accumulation of any nitroso-derivatives or NDAB (4-nitro-2,4-diazabutanal), indicating nearly complete mineralization. Pyrosequencing targeting the bacterial 16S rRNA genes revealed that the Rhizobium, Rhizobacter and Terrimonas population increased as the RDX degradation activity increased, suggesting their involvement in the degradation process. These findings imply that the nitrogen-fixing aerobic RDX degrading consortium is a valuable microbial resource for improving the detoxification of RDX-contaminated soil or groundwater, especially when combined with rhizoremediation. PMID:25661171

  4. Developments in metallic biodegradable stents.

    PubMed

    Hermawan, H; Dubé, D; Mantovani, D

    2010-05-01

    Interest in metallic degradable biomaterials research has been growing in the last decade. Both scientific journals and patent databases record a high increase in publications in this area. Biomedical implants with temporary function, such as coronary stents, are the targeted applications for this novel class of biomaterials. It is expected that stents made of degradable biomaterials, named biodegradable stents, will provide a temporary opening into a narrowed arterial vessel until the vessel remodels and will progressively disappear thereafter. Biodegradable stents made of metal have recently been progressed into preclinical tests in humans after their first introduction in early 2000s. By referring to patents and journal publications, this paper reviews the developments in biodegradable stents, with emphasis on those made of metals, starting from the first design ideas to validation testing. PMID:19815097

  5. Simultaneous nitritation and p-nitrophenol removal using aerobic granular biomass in a continuous airlift reactor.

    PubMed

    Jemaat, Zulkifly; Suárez-Ojeda, María Eugenia; Pérez, Julio; Carrera, Julián

    2013-12-01

    The chemical and petrochemical industries produce wastewaters containing ammonium and phenolic compounds. Biological treatment of these wastewaters could be problematic due to the possible inhibitory effects exerted by phenolic compounds. The feasibility of performing simultaneous nitritation and p-nitrophenol (PNP) biodegradation using a continuous aerobic granular reactor was evaluated. A nitrifying granular sludge was bioaugmented with a PNP-degrading floccular sludge, while PNP was progressively added to the feed containing a high ammonium concentration. Nitritation was sustained throughout the operational period with ca. 85% of ammonium oxidation and less than 0.3% of nitrate in the effluent. PNP biodegradation was unstable and the oxygen limiting condition was found to be the main explanation for this unsteadiness. An increase in dissolved oxygen concentration from 2.0 to 4.5 mg O2 L(-1) significantly enhanced PNP removal, achieving total elimination. Acinetobacter genus and ammonia-oxidising bacteria were the predominant bacteria species in the granular biomass. PMID:24177164

  6. Aerobic microbial enhanced oil recovery

    SciTech Connect

    Torsvik, T.; Gilje, E.; Sunde, E.

    1995-12-31

    In aerobic MEOR, the ability of oil-degrading bacteria to mobilize oil is used to increase oil recovery. In this process, oxygen and mineral nutrients are injected into the oil reservoir in order to stimulate growth of aerobic oil-degrading bacteria in the reservoir. Experiments carried out in a model sandstone with stock tank oil and bacteria isolated from offshore wells showed that residual oil saturation was lowered from 27% to 3%. The process was time dependent, not pore volume dependent. During MEOR flooding, the relative permeability of water was lowered. Oxygen and active bacteria were needed for the process to take place. Maximum efficiency was reached at low oxygen concentrations, approximately 1 mg O{sub 2}/liter.

  7. Petroleum biodegradation in marine environments.

    PubMed

    Harayama, S; Kishira, H; Kasai, Y; Shutsubo, K

    1999-08-01

    Petroleum-based products are the major source of energy for industry and daily life. Petroleum is also the raw material for many chemical products such as plastics, paints, and cosmetics. The transport of petroleum across the world is frequent, and the amounts of petroleum stocks in developed countries are enormous. Consequently, the potential for oil spills is significant, and research on the fate of petroleum in a marine environment is important to evaluate the environmental threat of oil spills, and to develop biotechnology to cope with them. Crude oil is constituted from thousands of components which are separated into saturates, aromatics, resins and asphaltenes. Upon discharge into the sea, crude oil is subjected to weathering, the process caused by the combined effects of physical, chemical and biological modification. Saturates, especially those of smaller molecular weight, are readily biodegraded in marine environments. Aromatics with one, two or three aromatic rings are also efficiently biodegraded; however, those with four or more aromatic ring are quite resistant to biodegradation. The asphaltene and resin fractions contain higher molecular weight compounds whose chemical structures have not yet been resolved. The biodegradability of these compounds is not yet known. It is known that the concentrations of available nitrogen and phosphorus in seawater limit the growth and activities of hydrocarbon-degrading microorganisms in a marine environment. In other words, the addition of nitrogen and phosphorus fertilizers to an oil-contaminated marine environment can stimulate the biodegradation of spilled oil. This notion was confirmed in the large-scale operation for bioremediation after the oil spill from the Exxon Valdez in Alaska. Many microorganisms capable of degrading petroleum components have been isolated. However, few of them seem to be important for petroleum biodegradation in natural environments. One group of bacteria belonging to the genus

  8. Utilization of Triton X-100 and polyethylene glycols during surfactant-mediated biodegradation of diesel fuel.

    PubMed

    Wyrwas, Bogdan; Chrzanowski, Łukasz; Ławniczak, Łukasz; Szulc, Alicja; Cyplik, Paweł; Białas, Wojciech; Szymański, Andrzej; Hołderna-Odachowska, Aleksandra

    2011-12-15

    The hypothesis regarding preferential biodegradation of surfactants applied for enhancement of microbial hydrocarbons degradation was studied. At first the microbial degradation of sole Triton X-100 by soil isolated hydrocarbon degrading bacterial consortium was confirmed under both full and limited aeration with nitrate as an electron acceptor. Triton X-100 (600 mg/l) was utilized twice as fast for aerobic conditions (t(1/2)=10.3h), compared to anaerobic conditions (t(1/2)=21.8h). HPLC/ESI-MS analysis revealed the preferential biodegradation trends in both components classes of commercial Triton X-100 (alkylphenol ethoxylates) as well as polyethylene glycols. The obtained results suggest that the observed changes in the degree of ethoxylation for polyethylene glycol homologues occurred as a consequence of the 'central fission' mechanism during Triton X-100 biodegradation. Subsequent experiments with Triton X-100 at approx. CMC concentration (150 mg/l) and diesel oil supported our initial hypothesis that the surfactant would become the preferred carbon source even for hydrocarbon degrading bacteria. Regardless of aeration regimes Triton X-100 was utilized within 48-72 h. Efficiency of diesel oil degradation was decreased in the presence of surfactant for aerobic conditions by approx. 25% reaching 60 instead of 80% noted for experiments without surfactant. No surfactant influence was observed for anaerobic conditions. PMID:21996621

  9. Biodegradation of chlorinated ethenes at a karst site in middle Tennessee

    USGS Publications Warehouse

    Byl, Thomas Duane; Williams, Shannon D.

    2000-01-01

    This report presents results of field and laboratory investigations examining the biodegradation of chlorinated ethenes in a karst aquifer contaminated with trichloroethylene (TCE). The study site, located in Middle Tennessee, was selected because of the presence of TCE degradation byproducts in the karst aquifer and available site hydrologic and chlorinated-ethene information. Additional chemical, biological, and hydrologic data were gathered to evaluate whether the occurrence of TCE degradation byproducts in the karst aquifer was the result of biodegradation within the aquifer or simply transport into the aquifer. Geochemical analysis established that sulfate-reducing conditions, essential for reductive dechlorination of chlorinated solvents, existed in parts of the contaminated karst aquifer. Other areas of the aquifer fluctuated between anaerobic and aerobic conditions and contained compounds associated with cometabolism, such as ethane, methane, ammonia, and dissolved oxygen. A large, diverse bacteria population inhabits the contaminated aquifer. Bacteria known to biodegrade TCE and other chlorinated solvents, such as sulfate-reducers, methanotrophs, and ammonia-oxidizers, were identified from karst-aquifer water using the RNA-hybridization technique. Results from microcosms using raw karst-aquifer water found that aerobic cometabolism and anaerobic reductive-dechlorination degradation processes were possible when appropriate conditions were established in the microcosms. These chemical and biological results provide circumstantial evidence that several biodegradation processes are active in the aquifer. Additional site hydrologic information was developed to determine if appropriate conditions persist long enough in the karst aquifer for these biodegradation processes to be significant. Continuous monitoring devices placed in four wells during the spring of 1998 indicated that pH, specific conductance, dissolved oxygen, and oxidation-reduction potentials

  10. WWOX loss activates aerobic glycolysis

    PubMed Central

    Abu-Remaileh, Muhannad; Seewaldt, Victoria L; Aqeilan, Rami I

    2015-01-01

    Cancer cells undergo reprogramming of glucose metabolism to limit energy production to glycolysis—a state known as “aerobic glycolysis.” Hypoxia-inducible factor 1 (HIF1α) is a transcription factor that regulates many genes responsible for this switch. As discussed here, new data suggest that the tumor suppressor WW domain-containing oxidoreductase (WWOX) modulates HIF1α, thereby regulating this metabolic state. PMID:27308416

  11. Biodegradation and bioaccumulation of phthalates

    SciTech Connect

    Scholz, N.; Diefenbach, R.

    1995-12-31

    Phthalate esters very often are considered as persistent in the environment. This view is supported by an assumed lack of biodegradability, the high log K{sub ow} values and the assumed high bioaccumulation potential. Results are presented which show phthalates esters to be readily biodegradable even with a non-adapted inoculum. Combined with a lack of relevant bioaccumulation in aquatic organisms, a reconsideration of the environmental impact of these substances is necessary. Special prerequisites for testing poorly water soluble substances are also discussed.

  12. Integrated biological (anaerobic-aerobic) and physico-chemical treatment of baker's yeast wastewater.

    PubMed

    Kalyuzhnyi, S; Gladchenko, M; Starostina, E; Shcherbakov, S; Versprille, B

    2005-01-01

    The UASB reactor (35 degrees C) was quite efficient for removal of bulk COD (52-74%) from simulated (on the basis of cultivation medium from the first separation process) general effluent of baker's yeast production (the average organic loading rates varied from 8.1 to 16 g COD/l/d). The aerobic-anoxic biofilter (19-23 degrees C) can be used for removal of remaining BOD and ammonia from anaerobic effluents; however, it suffered from COD-deficiency to fulfil denitrification requirements. To balance COD/N ratio, some bypass (approximately 10%) of anaerobically untreated general effluent should be added to the biofilter feed. The application of iron (III)-, aluminium- or calcium-induced coagulation for post-treatment of aerobic-anoxic effluents can fulfil the limits for discharge to sewerage (even for colour mainly exerted by hardly biodegradable melanoidins), however, the required amounts of coagulants were relatively high. PMID:16459801

  13. Organic micropollutants in aerobic and anaerobic membrane bioreactors: Changes in microbial communities and gene expression.

    PubMed

    Harb, Moustapha; Wei, Chun-Hai; Wang, Nan; Amy, Gary; Hong, Pei-Ying

    2016-10-01

    Organic micro-pollutants (OMPs) are contaminants of emerging concern in wastewater treatment due to the risk of their proliferation into the environment, but their impact on the biological treatment process is not well understood. The purpose of this study is to examine the effects of the presence of OMPs on the core microbial populations of wastewater treatment. Two nanofiltration-coupled membrane bioreactors (aerobic and anaerobic) were subjected to the same operating conditions while treating synthetic municipal wastewater spiked with OMPs. Microbial community dynamics, gene expression levels, and antibiotic resistance genes were analyzed using molecular-based approaches. Results showed that presence of OMPs in the wastewater feed had a clear effect on keystone bacterial populations in both the aerobic and anaerobic sludge while also significantly impacting biodegradation-associated gene expression levels. Finally, multiple antibiotic-type OMPs were found to have higher removal rates in the anaerobic MBR, while associated antibiotic resistance genes were lower. PMID:27441825

  14. Metagenomics of Hydrocarbon Resource Environments Indicates Aerobic Taxa and Genes to be Unexpectedly Common

    PubMed Central

    2013-01-01

    Oil in subsurface reservoirs is biodegraded by resident microbial communities. Water-mediated, anaerobic conversion of hydrocarbons to methane and CO2, catalyzed by syntrophic bacteria and methanogenic archaea, is thought to be one of the dominant processes. We compared 160 microbial community compositions in ten hydrocarbon resource environments (HREs) and sequenced twelve metagenomes to characterize their metabolic potential. Although anaerobic communities were common, cores from oil sands and coal beds had unexpectedly high proportions of aerobic hydrocarbon-degrading bacteria. Likewise, most metagenomes had high proportions of genes for enzymes involved in aerobic hydrocarbon metabolism. Hence, although HREs may have been strictly anaerobic and typically methanogenic for much of their history, this may not hold today for coal beds and for the Alberta oil sands, one of the largest remaining oil reservoirs in the world. This finding may influence strategies to recover energy or chemicals from these HREs by in situ microbial processes. PMID:23889694

  15. Ecotoxicity and biodegradability of antielectrostatic dicephalic cationic surfactants.

    PubMed

    Piętka-Ottlik, Magdalena; Frąckowiak, Renata; Maliszewska, Irena; Kołwzan, Barbara; Wilk, Kazimiera A

    2012-11-01

    Four series of dicephalic cationic surfactants, considered as new antielectrostatic agents have been investigated in order to establish their toxicity and biodegradability. Among them N,N-bis[3,3'-(dimethylamine)propyl]alkylamides, N,N-bis[3,3'-(dimethylamine)propyl]alkylamide dihydrochlorides, N,N-bis[3,3'-(trimethylammonio)propyl]alkylamide dibromides and N,N-bis[3,3'-(trimethylammonio)propyl]alkylamide dimethylsulphates with different hydrophobic chain length (n-C(9)H(19) to n-C(15)H(31)) and type of counterion (chloride, bromide and methylsulfate) have been studied. The inhibitory effect against microorganisms has been examined using model gram-positive and gram-negative bacteria, and yeasts. None of the tested surfactants have shown antimicrobial activity against gram-negative bacteria (Escherichia coli, Pseudomonas putida) and yeasts (Saccharomyces cerevisiae, Rhodotorula glutinis) at a concentration below 1000 μg mL(-1), however some of them were moderately active against gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis). The Microtox® test was successfully applied to measure EC(50) values of the studied dicephalic cationic surfactants. Their toxicity to Vibrio fischeri depended upon the alkanoyl chain length with the EC(50) values in a range of 2.6-980 mg L(-1). N,N-bis[3,3'-(dimethylamine)propyl]alkylamide dihydrochlorides 2a-b and N,N-bis[3,3'-(trimethylammonio)propyl]alkylamide dibromides 3a-b comprising n-decanoyl and n-dodecanoyl hydrophobic tails appeared to be the least toxic. Furthermore, the biodegradability under aerobic conditions of 2a-b, 3a-b was evaluated using OECD Method 301F. According to the obtained results 2a, 3a-3b can be considered as almost readily biodegradable and they are not expected to be persistent in the environment. Additionally, partial biodegradation was observed for 2b, indicating its possible biodegradation in wastewater treatment systems. PMID:22743183

  16. BIODEGRADATION OF TRICHLOROETHYLENE AND INVOLVEMENT OF AN AROMATIC BIODEGRADATIVE PATHWAY

    EPA Science Inventory

    Biodegradation of trichloroethylene (TCE) by the bacterial isolate strain G4 resulted in complete dechlorination of the compound as indicated by the production of inorganic chloride. A component of the water from which strain G4 was isolated that was required for TCE degradation ...

  17. Methods to determine aerobic endurance.

    PubMed

    Bosquet, Laurent; Léger, Luc; Legros, Patrick

    2002-01-01

    Physiological testing of elite athletes requires the correct identification and assessment of sports-specific underlying factors. It is now recognised that performance in long-distance events is determined by maximal oxygen uptake (V(2 max)), energy cost of exercise and the maximal fractional utilisation of V(2 max) in any realised performance or as a corollary a set percentage of V(2 max) that could be endured as long as possible. This later ability is defined as endurance, and more precisely aerobic endurance, since V(2 max) sets the upper limit of aerobic pathway. It should be distinguished from endurance ability or endurance performance, which are synonymous with performance in long-distance events. The present review examines methods available in the literature to assess aerobic endurance. They are numerous and can be classified into two categories, namely direct and indirect methods. Direct methods bring together all indices that allow either a complete or a partial representation of the power-duration relationship, while indirect methods revolve around the determination of the so-called anaerobic threshold (AT). With regard to direct methods, performance in a series of tests provides a more complete and presumably more valid description of the power-duration relationship than performance in a single test, even if both approaches are well correlated with each other. However, the question remains open to determine which systems model should be employed among the several available in the literature, and how to use them in the prescription of training intensities. As for indirect methods, there is quantitative accumulation of data supporting the utilisation of the AT to assess aerobic endurance and to prescribe training intensities. However, it appears that: there is no unique intensity corresponding to the AT, since criteria available in the literature provide inconsistent results; and the non-invasive determination of the AT using ventilatory and heart rate

  18. Biodegradability and toxicity assessment of bleach plant effluents treated anaerobically.

    PubMed

    Chaparro, T R; Botta, C M; Pires, E C

    2010-01-01

    As part of an experimental project on the treatment of bleach plant effluents the results of biodegradability and toxicity assessment of effluents from a bench-scale horizontal anaerobic immobilized bioreactor (HAIB) are discussed in this paper. The biodegradability of the bleach plant effluents from a Kraft pulp mill treated in the HAIB was evaluated using the modified Zahn-Wellens test. The inoculum came from a pulp mill wastewater treatment plant and the dissolved organic carbon (DOC) was used as the indicator of organic matter removal. The acute and chronic toxicity removal during the anaerobic treatment was estimated using Daphnia similis and Ceriodaphnia silvestrii respectively. Moreover, the evaluation of chromosome aberrations (CA), micronucleus frequencies (MN) and mitotic index (IM) in Allium cepa cells were used as genotoxicity indicators. The results indicate that the effluents from the anaerobic reactor are amenable to aerobic polishing. Acute and chronic toxicity were reduced by 90 and 81%, respectively. The largest CA and MN incidence in the meristematic cells of A. cepa were observed after exposure to the raw bleach plant effluent. The HAIB was able to reduce the acute and chronic toxicity as well as chromosome aberrations and the occurrence of micronucleus. PMID:20861545

  19. Biodegradation of the phthalates and their esters by bacteria.

    PubMed Central

    Keyser, P; Pujar, B G; Eaton, R W; Ribbons, D W

    1976-01-01

    Recent studies on the biodegradation phthalate esters in natural ecosystems, sewage, and laboratory cultures are reviewed. There is ample evidence to demonstrate that bacteria are major elements in the biodegradative processes and that in most situations complete oxidation of the aromatic ring occurs; much less is known about the catabolism of the alcoholic moiety, e.g., 2-ethylhexanol. Evidence is presented to support catabolic pathways in pseudomonads and micrococci that are initiated by successive hydrolyses of the diesters to give the phthalate anion. Thereafter a dioxygenase catalyzes the formation of 4,5-dihydro-4,5-dihydroxyphthalate, which is oxidized by an NAD-dependent dehydrogenase to give 4,5-dihydroxyphthalate, Protocatechuate, formed by decarboxylation of 4,5-dihydroxyphthalate, is the substrate for ring cleavage enzymes. Whereas flurorescent pseudomonads use the beta-ketoadipate pathway, the nonfluorescent strains and micrococci examined use of meta-cleavage (4,5-) route. All the intermediates proposed have been accumulated by enzymes purified from Pseudomonas fluorescens. Isophthalate and terephthalate (anions) are readily used as carbon sources by aerobic bacteria, and preliminary evidence is consistent with catabolic routes for these isomers converging at the ring-cleavage substrate protocatechuate. Some possible effects and interactions of synthetic organic chemicals with the natural microflora, and the influence of other vectors, is discussed in relation to the maintenance of the carbon cycle and environmental pollution. PMID:829485

  20. Biodegradation of microbial and synthetic polyesters by fungi.

    PubMed

    Kim, D Y; Rhee, Y H

    2003-05-01

    A variety of biodegradable polyesters have been developed in order to obtain useful biomaterials and to reduce the impact of environmental pollution caused by the large-scale accumulation of non-degradable waste plastics. Polyhydroxyalkanoates, poly(epsilon-caprolactone), poly( l-lactide), and both aliphatic and aromatic polyalkylene dicarboxylic acids are examples of biodegradable polyesters. In general, most aliphatic polyesters are readily mineralized by a number of aerobic and anaerobic microorganisms that are widely distributed in nature. However, aromatic polyesters are more resistant to microbial attack than aliphatic polyesters. The fungal biomass in soils generally exceeds the bacterial biomass and thus it is likely that fungi may play a considerable role in degrading polyesters, just as they predominantly perform the decomposition of organic matter in the soil ecosystem. However, in contrast to bacterial polyester degradation, which has been extensively investigated, the microbiological and environmental aspects of fungal degradation of polyesters are unclear. This review reports recent advances in our knowledge of the fungal degradation of microbial and synthetic polyesters and discusses the ecological importance and contribution of fungi in the biological recycling of waste polymeric materials in the biosphere. PMID:12743758