WorldWideScience

Sample records for bioventing

  1. Case Study: del Amo Bioventing

    Science.gov (United States)

    The attached presentation discusses the fundamentals of bioventing in the vadose zone. The basics of bioventing are presented. The experience to date with the del Amo Superfund Site is presented as a case study.

  2. MANUAL: BIOVENTING PRINCIPLES AND PRACTICE VOLUME II. BIOVENTING DESIGN

    Science.gov (United States)

    The results from bioventing research and development efforts and from the pilot-scale bioventing systems have been used to produce this two-volume manual. Although this design manual has been written based on extensive experience with petroleum hydrocarbons (and thus, many exampl...

  3. MANUAL: BIOVENTING PRINCIPLES AND PRACTICE VOLUME I. BIOVENTING PRINCIPLES

    Science.gov (United States)

    Bioventing is the process of aerating soils to stimulate in situ biological activity and promote bioremediation. Bioventing typically is applied in situ to the vadose zone and is applicable to any chemical that can be aerobically biodegraded but to date has primarily been impleme...

  4. The use of anhydrous ammonia for bioventing

    Energy Technology Data Exchange (ETDEWEB)

    Zytner, R.G.; Hallman, M.; Gimenez, B.F.; Jennings, R.; Leek, K. [Guelph Univ., ON (Canada). Faculty of Graduate Studies

    2002-07-01

    Soils contaminated with hydrocarbons can be effectively treated using bioventing remediation technology, an ideal method for removing residual contamination left by soil vapour extraction (SVE). Bioventing uses low or intermitted air flow rates to produce oxygen-rich conditions in the vadose zone, thereby promoting the formation of micro-organisms that can mineralize the hydrocarbons if enough nutrients are present. There is concern regarding the use of nutrients (the addition of nitrogen) to the subsurface because current applications methods cannot uniformly disperse nitrogen throughout the entire subsurface. Two research studies are being conducted using gasoline contaminated soil to address this concern. The first phase of the study focuses on how to best deliver nitrogen to the subsurface. Injecting anhydrous ammonia into the contaminated surface was one suggestion for stimulating the growth of hydrocarbon degraders. SVE extraction well models indicated this was an effective and safe way to disperse nitrogen. The second phase of the study involved the use of respirometers to compare total petroleum hydrocarbon (TPH) degradation with nitrogen additions in the form of NH{sub 4}Cl or anhydrous ammonia. The respirometers were run for about 1 month after which time it was determined that the use of anhydrous ammonia is an effective method to promote bioventing.

  5. OPTIMIZING BIOVENTING IN SHALLOW VADOSE ZONES AND COLD CLIMATES

    Science.gov (United States)

    This paper describes a bioventing study design and initial activities applied to a JP-4 jet fuel spill at Eielson Air Force Base, Alaska. The primary objectives of the project were to investigate the feasibility of using bioventing technology to remediate JP-4 jet fuel contaminat...

  6. Bioventing of gasoline-contaminated soil under varied laboratory conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hallman, M.; Shewfelt, K. [Univ. of Guelph, School of Engineering, Guelph, Ontario (Canada); Lee, H. [Univ. of Guelph, Dept. of Environmental Biology, Guelph, Ontario (Canada); Zytner, R.G. [Univ. of Guelph, School of Engineering, Guelph, Ontario (Canada)

    2002-06-15

    Bioventing is becoming a popular in situ soil remediation technology for the treatment of hydrocarbon-contaminated soil. Bioventing relies on enhancing the growth of indigenous microorganisms, which can mineralize the contaminant in the presence of sufficient nutrients. Although bioventing is currently being used as a remediation technology, there are some important questions that remain to be answered in order to optimize the process. These questions include the optimum soil moisture content, type and amount of nutrients necessary, and the best means of producing these conditions in the field. To address these questions, two distinct phases of experiments were conducted. The first experimental phase was designed to determine the optimum moisture content, C:N ratio and form of nitrogen supply for this soil. Using approximately 200g of contaminated soil in each of a series of sealed respirometers, microbial degradation of gasoline under bioventing conditions was quantified for C:N ratios of 5, 10 and 20:1, using varying mixtures of NH{sub 4}{sup +} - and NO{sub 3}{sup -} -N. The results of the studies indicated that the optimum soil moisture content was 15 wt%, with a C:N ratio of 10:1, using a 100% ammonium application. Using the results of the first phase, a second phase of laboratory research was initiated. Five mesoscale reactors have been developed to simulate the bioventing process that takes place in the field. These reactors are filled with approximately 4kg of gasoline-contaminated soil. The initial results are favourable. (author)

  7. Optimization of nitrogen for soil bioventing of gasoline contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Shewfelt, K.; Zytner, R. G. [University of Guelph, School of Engineering, Guelph, ON (Canada); Lee, H. [University of Guelph, Dept. of Environmental Biology, Guelph, ON (Canada)

    2005-01-01

    Bioventing, a promising in situ technology that uses low or intermittent airflow rates to produce oxygen-rich conditions in the aerated zone of the soil, promotes the growth of indigenous microorganisms, which degrade hydrocarbon contaminants that are frequently found around underground storage tanks. This study was undertaken to determine the optimum form and concentration of nitrogen that will effectively stimulate naturally occurring bacteria and fungi to obtain the highest degradation possible in a soil system using bioventing to treat gasoline-contaminated soil. Results showed that biodegradation was limited at high C:N ratios by the availability of nitrogen and at low C:N ratios by acidification. Aerobic bacteria were responsible for most of the biodegradation that occurred. Indigenous fungi had no significant effect on the rate of biodegradation. 47 refs., 7 tabs., 1 fig.

  8. Sustainable Horizontal Bioventing and Vertical Biosparging Implementation (Invited)

    Science.gov (United States)

    Leu, J.; Lin, J.; Ferris, S.

    2013-12-01

    A former natural gas processing site with total petroleum hydrocarbons (TPH) and benzene, toluene, ethylbenzene, and xylene (BTEX) impacts in both soil and groundwater was partially excavated to remove 2,400 cubic yards of impacted soil. However, due to active natural gas pipelines within the impacted footprint, excavation was discontinued and an area of impacted soil containing maximum concentrations of 5,000 mg/kg gasoline-range organics (GRO), 8,600 mg/kg diesel-range organics (DRO), and 130 mg/kg motor oil-range organics (ORO). Groundwater was impacted with concentrations up to 2,300 μg/L GRO and 4,200 μg/L DRO remained in place. Taking advantage of the open excavation, horizontal-screened piping was placed in the backfill to deliver air for bioventing, which resulted in successful remediation of soil in a physically inaccessible area. The combined use of excavation of the source area, bioventing of surrounding inaccessible soil, and biosparging of the groundwater and smear zone resulted in nearing a no-further-action status at the site. The sustainable bioventing system consisted of one 3-HP blower and eight horizontal air injection wells. Five dual-depth nested vapor monitoring points (VMPs) were installed at 5 feet and 10 feet below ground surface as part of the monitoring system for human health and system performance. The bioventing system operated for one year followed by a three-month rebound test. During the one-year operation, air flow was periodically adjusted to maximize removal of volatile organic compounds (VOCs) from the vent wells with elevated photo-ionization detector readings. After the bioventing successfully remediated the inaccessible impacted soil, the biosparging system incorporated the pre-existing bioventing unit with an upgraded 5-HP blower and three vertical biosparging wells to biodegrade dissolved phase impacts in the groundwater. The subsequent monitoring system includes the VMPs, the air injection wells, and four groundwater

  9. Bioventing remediation and ecotoxicity evaluation of phenanthrene-contaminated soil.

    Science.gov (United States)

    García Frutos, F Javier; Escolano, Olga; García, Susana; Babín, Mar; Fernández, M Dolores

    2010-11-15

    The objectives of soil remediation processes are usually based on threshold levels of soil contaminants. However, during remediation processes, changes in bioavailability and metabolite production can occur, making it necessary to incorporate an ecotoxicity assessment to estimate the risk to ecological receptors. The evolution of contaminants and soil ecotoxicity of artificially phenanthrene-contaminated soil (1000 mg/kg soil) during soil treatment through bioventing was studied in this work. Bioventing was performed in glass columns containing 5.5 kg of phenanthrene-contaminated soil and uncontaminated natural soil over a period of 7 months. Optimum conditions of mineralisation (humidity=60% WHC; C/N/P=100:20:1) were determined in a previous work. The evolution of oxygen consumption, carbon dioxide production, phenanthrene concentration and soil toxicity were studied on sacrificed columns at periods of 0, 3 and 7 months. Toxicity to soil and aquatic organisms was determined using a multispecies system in the soil columns (MS-3). In the optimal bioventing treatability test, we obtained a reduction rate in phenanthrene concentration higher that 93% after 7 months of treatment. The residual toxicity obtained at the end of the treatment was not attributed to the low phenanthrene concentration, but to the ammonia used to restore the optimal C/N ratio.

  10. Application of bioventing at a fuel oil impacted site

    International Nuclear Information System (INIS)

    Misdelivery of approximately 8,700 gallons of fuel oil into an underground storage tank compliance monitoring well at a manufacturing facility in the Piedmont Physiographic Province of Virginia resulted in contamination of site soils and ground water. Attempts to remediate the site using conventional ground-water pump and treat technology succeeded in containing the fuel oil within the site boundaries, but did little to remove soil residual and dissolved phase hydrocarbon. Bioventing was considered as an option to address the residual hydrocarbon in the vadose zone. Results of a pilot test suggested that a viable indigenous population of heterotrophic organisms capable of utilizing hydrocarbon as a cell growth and energy source was present in the subsurface. Based on this conclusion and the data generated in the pilot test, a bioventing system was designed and installed at the site. At the conclusion of six months of operation, 6,097 kg of hydrocarbon were removed by in situ biodegradation, 30 kg by vacuum extraction, and 4 kg by separate recovery

  11. Anaerobic bioventing of unsaturated zone contaminated with DDT and DNT.

    Science.gov (United States)

    Shah, J K; Sayles, G D; Suidan, M T; Mihopoulos, P; Kaskassian, S

    2001-01-01

    Initial degradation of highly chlorinated compounds and nitroaromatic compounds found in munition waste streams is accelerated under anaerobic conditions followed by aerobic treatment of the degradation products. The establishment of anaerobic environment in a vadose zone can be accomplished by feeding appropriate anaerobic gas mixture, i.e., "anaerobic bioventing". The gas mixture contains an electron donor for the reduction of these compounds. Lab scale study was conducted to evaluate potential of anaerobic bioventing for the treatment of an unsaturated zone contaminated with 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and 2,4-dinitrotoluene (DNT). Hydrogen was used as the electron donor. Using the soil columns innoculate with anaerobic microorganisms, it was observed that by feeding a gas mixture of 1% hydrogen, 1% carbon dioxide and nitrogen, methanogenic conditions were established and DDT was reductively dechlorinated. 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD) accumulated as the intermediate product. The half life of DDT was calculated to be 8.5 months. DNT completely disappeared after six months of operation and no intermediates could be detected.

  12. Investigations into the application of a combination of bioventing and biotrickling filter technologies for soil decontamination processes--a transition regime between bioventing and soil vapour extraction.

    Science.gov (United States)

    Magalhães, S M C; Ferreira Jorge, R M; Castro, P M L

    2009-10-30

    Bioventing has emerged as one of the most cost-effective in situ technologies available to address petroleum light-hydrocarbon spills, one of the most common sources of soil pollution. However, the major drawback associated with this technology is the extended treatment time often required. The present study aimed to illustrate how an intended air-injection bioventing technology can be transformed into a soil vapour extraction effort when the air flow rates are pushed to a stripping mode, thus leading to the treatment of the off-gas resulting from volatilisation. As such, a combination of an air-injection bioventing system and a biotrickling filter was applied for the treatment of contaminated soil, the latter aiming at the treatment of the emissions resulting from the bioventing process. With a moisture content of 10%, soil contaminated with toluene at two different concentrations, namely 2 and 14 mg g soil(-1), were treated successfully using an air-injection bioventing system at a constant air flow rate of ca. 0.13 dm(3) min(-1), which led to the removal of ca. 99% toluene, after a period of ca. 5 days of treatment. A biotrickling filter was simultaneously used to treat the outlet gas emissions, which presented average removal efficiencies of ca. 86%. The proposed combination of biotechnologies proved to be an efficient solution for the decontamination process, when an excessive air flow rate was applied, reducing both the soil contamination and the outlet gas emissions, whilst being able to reduce the treatment time required by bioventing only.

  13. Flow, Transport and Biodegradation of Toluene During Bioventing

    Institute of Scientific and Technical Information of China (English)

    隋红; 徐世民; 李鑫钢; 姜斌; 黄国强

    2004-01-01

    Bioventing is conducted on one-dimensional soil columns. A numerical model is developed for simulating the mass exchange, adivective and dispersive transport and biodegradation of toluene. The model parameters are estimated independently through laboratory batch experiments, or from literature. Simulations are found to provide reasonable agreement with experimental data. Experimental results show that toluene removal due to biodegradiation is more important at the later stage. The total cleanup time when NAPL (non-aqueous phase liquid) phase exists was twice more than that without NAPL. Sensitivity analysis of parameters suggests that model predictions are mainly dependent on mass transfer coefficient and microbial parameters, such as the half-saturation coefficient and maximum specific substrate utilization rate.

  14. A study on cometabolic bioventing for the in situ remediation of trichloroethylene.

    Science.gov (United States)

    Sui, Hong; Li, Xingang; Huang, Guoqiang; Jiang, Bin

    2006-01-01

    Cometabolic bioventing for removal of TCE in the unsaturated zone was studied in a soil column study using methane as growth substrate. A numerical model was developed for simulating the behavior of TCE during cometabolic bioventing. The model parameters were estimated independently through laboratory batch experiments or from the literature. Simulations were found to provide reasonable agreement with the experimental data. The experimental data show that a total TCE remediation efficiency of over 95% was obtained. The volatilization-to-biodegradation ratio of TCE was about 7:1 and T ( c ) values ranging from 0.0078 to 0.07 were obtained in this methane-driven system. Due to the toxicity of the high TCE concentrations to the microbial biomass in the initial stages of the experiment, cometabolic biodegradation was enhanced and was more efficient in the later stages of cometabolic bioventing.

  15. D-area oil seepage basin bioventing optimization test plan

    Energy Technology Data Exchange (ETDEWEB)

    Berry, C.J.; Radway, J.C.; Alman, D.; Hazen, T.C.

    1998-12-31

    The D Area Oil Seepage Basin (DOSB) was used from 1952 to 1975 for disposal of petroleum-based products (waste oils), general office and cafeteria waste, and apparently some solvents [trichloroethylene (TCE)/tetrachloroethylene (PCE)]. Numerous analytical results have indicated the presence of TCE and its degradation product vinyl chloride in groundwater in and around the unit, and of petroleum hydrocarbons in soils within the unit. The DOSB is slated for additional assessment and perhaps for environmental remediation. In situ bioremediation represents a technology of demonstrated effectiveness in the reclamation of sites contaminated with petroleum hydrocarbons and chlorinated solvents, and has been retained as an alternative for the cleanup of the DOSB. The Savannah River Site is therefore proposing to conduct a field treatability study designed to demonstrate and optimize the effectiveness of in situ microbiological biodegradative processes at the DOSB. The introduction of air and gaseous nutrients via two horizontal injection wells (bioventing) is expected to enhance biodegradation rates of petroleum components and stimulate microbial degradation of chlorinated solvents. The data gathered in this test will allow a determination of the biodegradation rates of contaminants of concern in the soil and groundwater, allow an evaluation of the feasibility of in situ bioremediation of soil and groundwater at the DOSB, and provide data necessary for the functional design criteria for the final remediation system.

  16. Numerical modeling of oxygen exclusion experiments of anaerobic bioventing

    Science.gov (United States)

    Mihopoulos, Philip G.; Suidan, Makram T.; Sayles, Gregory D.; Kaskassian, Sebastien

    2002-10-01

    A numerical and experimental study of transport phenomena underlying anaerobic bioventing (ABV) is presented. Understanding oxygen exclusion patterns in vadose zone environments is important in designing an ABV process for bioremediation of soil contaminated with chlorinated solvents. In particular, the establishment of an anaerobic zone of influence by nitrogen injection in the vadose zone is investigated. Oxygen exclusion experiments are performed in a pilot scale flow cell (2×1.1×0.1 m) using different venting flows and two different outflow boundary conditions (open and partially covered). Injection gas velocities are varied from 0.25×10 -3 to 1.0×10 -3 cm/s and are correlated with the ABV radius of influence. Numerical simulations are used to predict the collected experimental data. In general, reasonable agreement is found between observed and predicted oxygen concentrations. Use of impervious covers can significantly reduce the volume of forcing gas used, where an increase in oxygen exclusion efficiency is consistent with a decrease in the outflow area above the injection well.

  17. Numerical modeling of oxygen exclusion experiments of anaerobic bioventing.

    Science.gov (United States)

    Mihopoulos, Philip G; Suidan, Makram T; Sayles, Gregory D; Kaskassian, Sebastien

    2002-10-01

    A numerical and experimental study of transport phenomena underlying anaerobic bioventing (ABV) is presented. Understanding oxygen exclusion patterns in vadose zone environments is important in designing an ABV process for bioremediation of soil contaminated with chlorinated solvents. In particular, the establishment of an anaerobic zone of influence by nitrogen injection in the vadose zone is investigated. Oxygen exclusion experiments are performed in a pilot scale flow cell (2 x 1.1 x 0.1 m) using different venting flows and two different outflow boundary conditions (open and partially covered). Injection gas velocities are varied from 0.25 x 10(-3) to 1.0 x 10(-3) cm/s and are correlated with the ABV radius of influence. Numerical simulations are used to predict the collected experimental data. In general, reasonable agreement is found between observed and predicted oxygen concentrations. Use of impervious covers can significantly reduce the volume of forcing gas used, where an increase in oxygen exclusion efficiency is consistent with a decrease in the outflow area above the injection well. PMID:12400833

  18. Installation of a bio-venting remediation system using directionally drilled horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, L. [Morrow Environmental Consultants Inc., Burnaby, BC (Canada); Stolz, A.P. [Petro-Canada, Inc. (Canada)

    1997-12-31

    The installation of a remediation system for off-site contamination was discussed. The site was contaminated with gasoline and diesel from an abandoned bulk fuel storage and distribution terminal located near a highway. The dissolved phase hydrocarbon plume extended beneath several houses down gradient of the site. Bioventing was considered to be the only remediation option to recover the liquid phase hydrocarbons beneath the highway in a way that would satisfy all the clean-up objectives and the design constraints. Bioventing is closely related to soil vapour extraction (SVE). The main difference is that in bioventing, the mechanism for removal of contaminants is bio-degradation by indigenous bacteria, whereas in SVE, contaminants are simply removed by volatilization. Bioventing systems enhance the activity of the indigenous bacteria by inducing air flow in the subsurface through the use of vapour injection or extraction wells. Two horizontal vapour extraction wells were installed with a directional drill. A soil pile was utilized as a bio-filter for the extracted hydrocarbon vapours and a backfilled trench was used to inject vapours recovered from the soil pile to the subsurface. The total mass of hydrocarbons degraded by this system in 230 days was estimated to be 1,000 kg. It was concluded that under appropriate conditions the in-situ treatment of contaminated soil using directionally drilled wells can be justified on both economic and technical grounds. 3 refs., 1 tab., 5 figs.

  19. Bioventing of gasoline-contaminated soil: some questions to be answered

    Energy Technology Data Exchange (ETDEWEB)

    Bezerra, S.M.C.; Zytner, R.G. [Univ. of Guelph, School of Engineering, Guelph, Ontario (Canada)]. E-mail: sbezerra@uoguelph.ca; rzytner@uoguelph.ca

    2002-06-15

    Underground storage tank (UST) leakage is a big concern in the USA and Canada because gasoline-contaminated soil is a significant source of groundwater contamination. This threat is not confined to North America as locations like Sao Paulo (Brazil) have leakage rates similar to the North American average. The typical in-situ remediation technology used to remediate the contaminated soil is soil vapour extraction (SVE), but once tailing occurs, where the residual gasoline concentration still exceeds clean up levels, SVE becomes ineffective. Bioventing has emerged as one of the most cost-effective technologies currently available to address this tailing in the remediation of petroleum-contaminated sites. Bioventing is a source control treatment, which delivers air and nutrients through injection wells placed in contaminated areas, in order to stimulate the activity of the indigenous microorganisms. However, encouraging laboratory results have not always translated into similar outcomes when implemented in the field. A reason for this inconsistency is the scale-dependent phenomena that influence the bioventing process at the microscale, mesoscale, and macroscale. This paper intends to provide some insights about various research needs in order to improve the bioventing process, specifically related to predicting the time to reach site closure. (author)

  20. FIELD TEST OF NONFUEL HYDROCARBON BIOVENTING IN CLAYEY-SAND SOIL

    Science.gov (United States)

    A pilot-scale bioventing test was conducted at the Greenwood Chemical Superfund Site in Virginia. The characteristics of the site included clayey-sand soils and nonfuel organic contamination such as acetone, toluene, and naphthalene in the vadose zone. Based on the results of an...

  1. The effect of temperature on the bioventing of soil contaminated with toluene and decane

    NARCIS (Netherlands)

    Malina, G.; Grotenhuis, J.T.C.; Rulkens, W.H.

    1999-01-01

    The effect of temperature on evaporation and biodegradation rates during soil bioventing (SBV) was studied for a mixture of toluene and decane in bench-scale soil columns at a continuous air flow and consecutively at two different flow rates. The effect of temperature on SBV was monitored by GC head

  2. Bioventing pilot test results at the low point drain area, Offutt AFB, Nebraska.

    Science.gov (United States)

    Werner, F T; Walters, J E; Keefer, G B

    1997-11-21

    The purpose of this paper was to describe the application of bioventing technology at the LPD site at Offutt AFB, Nebraska and present the results of the 15-month pilot test. The preliminary tests indicated sufficient hydrocarbon contamination was present with the necessary soil characteristics to warrant an extended bioventing pilot test. The six month in situ respiration test indicated that progress was being made in reducing the TVH concentrations and biological activity was still occurring. Laboratory analysis of the final soil samples confirmed the reduction in TRPH and BTEX concentrations indicating that the site is close to complete remediation. However, owing to reduced air flow at greater distances from the VW, more biodegradation is still needed near MPB. The reduced biodegradation at MPB could also be due to the high water tables resulting from heavy rains during the summer and fall of 1993. The local water table was above the VW and MP screens for several months. The operation of the blower will continue until the site is completely remediated. The single VW pilot test at the LPD site at Offutt AFB has proven the effectiveness of bioventing in reducing TRPH and BTEX contamination in the subsurface. The installation, operation and maintenance costs were minimal. The effectiveness of this application has resulted in three additional bioventing applications at Offutt AFB including the first, full-scale system located in the state of Nebraska.

  3. BIOVENTING - Groundwater Aeration by Discontinuous Oxygen Gas Pulse Injections

    Science.gov (United States)

    Schirmer, M.

    2003-12-01

    Groundwater aeration by discontinuous oxygen gas pulse injections appears to be a promising concept for enhanced natural attenuation of dissolved contaminants that are susceptible for oxygenase enzyme attacks. Oxygen amendments facilitate indigenous microbiota to catabolize groundwater pollutants, such as aromatics, that are considered to be recalcitrant in absence of dissolved oxygen. As a rule, natural attenuation of many pollutants under aerobic conditions is considerably faster than under anaerobic conditions. Thus, enhancing the dissolved oxygen level appears to be worthwhile. In situ aeration of groundwater has been accomplished by air sparging, H2O2-supply, or by utilization of oxygen release compounds. However, continuous aeration of previously anaerobic groundwater is not desirable for several reasons: (a) economic efforts too high, (b) pollutant dislocation towards surface (desired only in air sparging), (c) risk of aquifer clogging (gas clogging, oxidation of ferrous iron, formation of bioslimes). In contrast, discontinuous oxygen gas sparging provides only for periodical groundwater aeration which is followed by microaerobic and suboxic conditions. Microaerobic conditions can prevail spatially (e.g., at plume fringes or within biofilms) or temporarily (e.g., at discontinuous bioventing). They still allow adapted bacteria to transform environmental pollutants to less toxic compounds, e.g., aromatic ring cleavage after dioxygenasis attack. Ring cleavage products, on the other hand, may be degraded more easily by anaerobic consortia than the initial aromatic compounds, making oxygen depletion periods highly intriguing in regard to an initiation of natural attenuation processes at plume fringes. In our work we outline the effect of oxygen depletion conditions on biodegradation of monchlorobenzene (MCB) as they occur subsequently to temporary aeration periods. For microaerobic conditions, relative to the oxygen supply, a stoichiometric transformation of MCB

  4. Bioventing at a heating oil spill site in Yellowknife, Northwest Territories

    Energy Technology Data Exchange (ETDEWEB)

    Barnette, M.; Das, D.; Clark, J. [EBA Engineering Consultants Ltd., Yellowknife, NT (Canada); Ziervogel, H. [EBA Engineering Consultants Ltd., Calgary, AB (Canada); Hayden, K. [WAM Development Group North, Yellowknife, NT (Canada)

    2005-07-01

    This paper discusses the application of a bioventing system used to treat soil and groundwater contaminated with diesel at a commercial property in Yellowknife. Contamination was caused by a broken pipe connected to an underground storage tank. A bioventing trial was proposed as the most economical method of remediating residual contamination following several years of product recovery. A background of earlier phased product recovery methods was provided. Sufficient heliotrophic bacteria was present in the groundwater for aerobic bioremediation of the petroleum hydrocarbon impacted soil and groundwater. Details of monitoring wells and recovery rates were presented, as well as installation procedures for the bioventing system, which included 3 air injection wells, 6 vadose zone observation wells and a blower fan with associated piping to blow air into the subsurface. The system operated for 12 days to establish subsurface conditions and evaluate effectiveness, and was subsequently used for various periods of duration from 2002 to 2004. Results for all periods of operation were provided. It was concluded that the system was effective in increasing subsurface oxygen concentrations to stimulate microbial bioremediation in the vadose zone soil. Estimated remediation time ranged from 3 to 5 years. The radius of influence of the system was in excess of 29 m. Changes in the water table meant that wells initially thought to be free of hydrocarbons became recontaminated. Further operations and monitoring of the bioventing system were recommended, including soil sampling to determine concentrations of hydrocarbons remaining at the site in comparison to other soil criteria. Monitoring costs were estimated at $10,000 per year. It was suggested that there was a potential for the application of this system in other northern contaminated areas. 3 figs.

  5. Bioventing at a heating oil spill site in Yellowknife, Northwest Territories

    International Nuclear Information System (INIS)

    This paper discusses the application of a bioventing system used to treat soil and groundwater contaminated with diesel at a commercial property in Yellowknife. Contamination was caused by a broken pipe connected to an underground storage tank. A bioventing trial was proposed as the most economical method of remediating residual contamination following several years of product recovery. A background of earlier phased product recovery methods was provided. Sufficient heliotrophic bacteria was present in the groundwater for aerobic bioremediation of the petroleum hydrocarbon impacted soil and groundwater. Details of monitoring wells and recovery rates were presented, as well as installation procedures for the bioventing system, which included 3 air injection wells, 6 vadose zone observation wells and a blower fan with associated piping to blow air into the subsurface. The system operated for 12 days to establish subsurface conditions and evaluate effectiveness, and was subsequently used for various periods of duration from 2002 to 2004. Results for all periods of operation were provided. It was concluded that the system was effective in increasing subsurface oxygen concentrations to stimulate microbial bioremediation in the vadose zone soil. Estimated remediation time ranged from 3 to 5 years. The radius of influence of the system was in excess of 29 m. Changes in the water table meant that wells initially thought to be free of hydrocarbons became recontaminated. Further operations and monitoring of the bioventing system were recommended, including soil sampling to determine concentrations of hydrocarbons remaining at the site in comparison to other soil criteria. Monitoring costs were estimated at $10,000 per year. It was suggested that there was a potential for the application of this system in other northern contaminated areas. 3 figs

  6. Evaluation of bioventing on a gasoline-ethanol contaminated undisturbed residual soil.

    Science.gov (United States)

    Osterreicher-Cunha, Patricia; Vargas, Eurípedes do Amaral; Guimarães, Jean Rémy Davée; de Campos, Tácio Mauro Pereira; Nunes, Cassiane Maria Ferreira; Costa, Ariovaldo; Antunes, Franklin dos Santos; da Silva, Maria Isabel Pais; Mano, Denise Maria

    2004-07-01

    Remediation methods for environmental contamination problems based on physical or chemical processes frequently present low efficiency and/or high costs. On the other hand, biological treatment is being proved to be an accessible alternative for soil and water remediation. Bioventing is commonly used for petroleum hydrocarbon (PHC) spills. This process provides better subsurface oxygenation, thus stimulating degradation by indigenous microorganisms. In Brazil, gasoline and ethanol are routinely mixed; some authors suggest that despite gasoline high degradability, its degradation in the aquifer is hindered by the presence of much rapidly degrading ethanol. The present study evaluates a bioventing treatment of a gasoline-ethanol contaminated undisturbed residual soil from Rio de Janeiro. Contamination and treatment effects were monitored by conventional microbiology methods, chemical analysis, and ground penetrating radar (GPR) measurements. Results of culturable bacterial population counts show the effect of contamination and bioventing on the microbiota of gasoline and gasoline-ethanol containing soils; however, GPR responses to these variations are not conclusive and still need to be assessed.

  7. Vapor Extraction/Bioventing Sequential Treatment of Soil Contaminated with Volatile and SemiVolatile Hydrocarbon Mixtures

    NARCIS (Netherlands)

    Malina, G.; Grotenhuis, J.T.C.; Rulkens, W.H.

    2002-01-01

    A cost-effective removal strategy was studied in bench-scale columns that involved vapor extraction and bioventing sequential treatment of toluene- and decane-contaminated soil. The effect of operating mode on treatment performance was examined at a continuous air flow and consecutively at two diffe

  8. Respiration testing for bioventing and biosparging remediation of petroleum contaminated soil and ground water

    International Nuclear Information System (INIS)

    Respiration tests were performed to measure the effect of subsurface aeration on the biodegradation rates of petroleum hydrocarbon contamination in vadose zone soils (bioventing) and ground water (biosparging). The aerobic biodegradation of petroleum contamination is typically limited by the absence of oxygen in the soil and ground water. Therefore, the goal of these bioremediation technologies is to increase the oxygen concentration in the subsurface and thereby enhance the natural aerobic biodegradation of the organic contamination. One case study for biosparging bioremediation testing is presented. At this site atmospheric air was injected into the ground water to increase the dissolved oxygen concentration in the ground water surrounding a well, and to aerate the smear zone above the ground water table. Aeration flow rates of 3 to 8 cfm (0.09 to 0.23 m3/min) were sufficient to increase the dissolved oxygen concentration. Petroleum hydrocarbon biodegradation rates of 32 to 47 microg/l/hour were calculated based on measurements of dissolved oxygen concentration in ground water. The results of this test have demonstrated that biosparging enhances the biodegradation of petroleum hydrocarbons, but the results as they apply to remediation are not known. Two case studies for bioventing respiration testing are presented

  9. Monitoring biodegradation of diesel fuel in bioventing processes using in situ respiration rate.

    Science.gov (United States)

    Lee, T H; Byun, I G; Kim, Y O; Hwang, I S; Park, T J

    2006-01-01

    An in situ measuring system of respiration rate was applied for monitoring biodegradation of diesel fuel in a bioventing process for bioremediation of diesel contaminated soil. Two laboratory-scale soil columns were packed with 5 kg of soil that was artificially contaminated by diesel fuel as final TPH (total petroleum hydrocarbon) concentration of 8,000 mg/kg soil. Nutrient was added to make a relative concentration of C:N:P = 100:10:1. One soil column was operated with continuous venting mode, and the other one with intermittent (6 h venting/6 h rest) venting mode. On-line O2 and CO2 gas measuring system was applied to measure O2 utilisation and CO2 production during biodegradation of diesel for 5 months. Biodegradation rate of TPH was calculated from respiration rate measured by the on-line gas measuring system. There were no apparent differences between calculated biodegradation rates from two columns with different venting modes. The variation of biodegradation rates corresponded well with trend of the remaining TPH concentrations comparing other biodegradation indicators, such as C17/pristane and C18/phytane ratio, dehydrogenase activity, and the ratio of hydrocarbon utilising bacteria to total heterotrophic bacteria. These results suggested that the on-line measuring system of respiration rate would be applied to monitoring biodegradation rate and to determine the potential applicability of bioventing process for bioremediation of oil contaminated soil.

  10. Monitoring biodegradation of diesel fuel in bioventing processes using in situ respiration rate.

    Science.gov (United States)

    Lee, T H; Byun, I G; Kim, Y O; Hwang, I S; Park, T J

    2006-01-01

    An in situ measuring system of respiration rate was applied for monitoring biodegradation of diesel fuel in a bioventing process for bioremediation of diesel contaminated soil. Two laboratory-scale soil columns were packed with 5 kg of soil that was artificially contaminated by diesel fuel as final TPH (total petroleum hydrocarbon) concentration of 8,000 mg/kg soil. Nutrient was added to make a relative concentration of C:N:P = 100:10:1. One soil column was operated with continuous venting mode, and the other one with intermittent (6 h venting/6 h rest) venting mode. On-line O2 and CO2 gas measuring system was applied to measure O2 utilisation and CO2 production during biodegradation of diesel for 5 months. Biodegradation rate of TPH was calculated from respiration rate measured by the on-line gas measuring system. There were no apparent differences between calculated biodegradation rates from two columns with different venting modes. The variation of biodegradation rates corresponded well with trend of the remaining TPH concentrations comparing other biodegradation indicators, such as C17/pristane and C18/phytane ratio, dehydrogenase activity, and the ratio of hydrocarbon utilising bacteria to total heterotrophic bacteria. These results suggested that the on-line measuring system of respiration rate would be applied to monitoring biodegradation rate and to determine the potential applicability of bioventing process for bioremediation of oil contaminated soil. PMID:16722077

  11. MICHIGAN SOIL VAPOR EXTRACTION REMEDIATION (MISER) MODEL: A COMPUTER PROGRAM TO MODEL SOIL VAPORT EXTRACTION AND BIOVENTING OF ORGANIC MATERIALS IN UNSATURATED GEOLOGICAL MATERIAL

    Science.gov (United States)

    This report describes the formulation, numerical development, and use of a multiphase, multicomponent, biodegradation model designed to simulate physical, chemical, and biological interactions occurring primarily in field scale soil vapor extraction (SVE) and bioventing (B...

  12. Monitoring laboratory-scale bioventing using synchronous scan fluorescence spectroscopy: analysis of the vapor phase.

    Science.gov (United States)

    Bachman, J; Kanan, S M; Patterson, H H

    2001-01-01

    Bioventing is an improved method of soil remediation that is being used with increasing frequency. In this paper, we refine techniques to measure the progress of petroleum hydrocarbon decomposition by monitoring vapor phase composition with synchronous scan fluorescence spectroscopy (SSFS). Analysis of the vapor phase has advantages compared to standard extraction techniques that require extensive sample handling and clean up. For comparison, hydrocarbon contamination in the soil was measured by analysis of Soxhlet extractions with gas chromatography-mass spectrometry (GC-MS). Comparison of the GC-MS and SSFS data showed that changes in hydrocarbon composition measured in the vapor phase provide an accurate measure of decomposition reactions taking place in the soil.

  13. Complete remediation of PCE contaminated unsaturated soils by sequential anaerobic-aerobic bioventing.

    Science.gov (United States)

    Mihopoulos, P G; Suidan, M T; Sayles, G D

    2001-01-01

    Bioventing principles have been applied to completely dechlorinate tetrachloroethylene vapors in the unsaturated zone in a sequential anaerobic-aerobic pattern. The aerobic step yields trans-DCE and VC as PCE reductive dechlorination byproducts, while TCE and cis-DCE are observed as intermediates. The aerobic step results in rapid oxidation of the VC and trans-DCE to carbon dioxide. Hydrogen was delivered in the gas phase as a reducing agent for the anaerobic step at levels of 1%, and oxygen at 4.2% was used as an electron acceptor in the aerobic step. PCE and VC half lives in the anaerobic and aerobic steps respectively, where less than 10 min.

  14. Benzene, toluene and p-xylene interactions and the role of microbial communities in remediation using bioventing

    Energy Technology Data Exchange (ETDEWEB)

    Sui, H. [Tianjin Univ., Tianjin (China). School of Chemical Engineering and Technology; Tianjin Univ., Tianjin (China). National Engineering Research Center for Distillation Technology; Li, X.G.; Jiang, B. [Tianjin Univ., Tianjin (China). National Engineering Research Center for Distillation Technology

    2005-04-01

    Bioventing is a promising in-situ soil remediation technology used to clean soils and groundwater contaminated by aromatic hydrocarbon components benzene, toluene and xylene (BTX). These contaminants are present at numerous hazardous waste sites. Bioventing provides enough oxygen to stimulate aerobic biodegradation by indigenous microorganisms. It is not constrained by contaminant volatility and can therefore be applied to contaminants that are readily biodegradable even if they are not highly volatile. This study examined the volatilization and biodegradation of BTX during bioventing from unsaturated soil. It focused on the occurrence of any substrate interaction and the effects of indigenous microbial inocula. The soil was inoculated with indigenous microorganisms obtained from the Dagang Oil Field in Tianjin, China. Then, different amounts of BTX were added to the soil in a stainless steel column through which carbon dioxide free air and pure nitrogen flowed. The volatilization-to-biodegradation ratios of BTX were 6:1, 2:1 and 2:1 respectively. After 3 weeks, the final concentration in the soil gas was 0.128 mg/L benzene, 0.377 mg/L toluene and 0.143 mg/L xylene. The substrate interactions that occurred were as follows: benzene and xylene degradation was accelerated while toluene was being degraded; and, the presence of xylene increased the lag period for benzene degradation. It was concluded that bioventing is an effective remediation technology for aromatic hydrocarbons and can significantly reduce the remediation time if target residual BTX concentration of 0.1 mg/L is to be reached. BTX removal becomes more significant with time, particularly when soils are inoculated with indigenous microbial communities from contaminated soil. 22 refs., 5 tabs., 7 figs.

  15. MICHIGAN SOIL VAPOR EXTRACTION REMEDIATION (MISER) MODEL: A COMPUTER PROGRAM TO MODEL SOIL VAPOR EXTRACTION AND BIOVENTING OF ORGANIC CHEMICALS IN UNSATURATED GEOLOGICAL MATERIAL

    Science.gov (United States)

    Soil vapor extraction (SVE) and bioventing (BV) are proven strategies for remediation of unsaturated zone soils. Mathematical models are powerful tools that can be used to integrate and quantify the interaction of physical, chemical, and biological processes occurring in field sc...

  16. BIODEGRADATION OF DIESEL OIL IN SOIL AND ITS ENHANCEMENT BY APPLICATION OF BIOVENTING AND AMENDMENT WITH BREWERY WASTE EFFLUENTS AS BIOSTIMULATION-BIOAUGMENTATION AGENTS

    Directory of Open Access Journals (Sweden)

    Samuel Agarry

    2015-02-01

    Full Text Available The purpose of this study is to investigate and evaluate the effects of natural bioattenuation, bioventing, and brewery waste effluents amendment as biostimulation-bioaugmentation agent on biodegradation of diesel oil in unsaturated soil. A microcosm system was constructed consisting of five plastic buckets containing 1 kg of soil, artificially contaminated or spiked with 10% w/w of diesel oil. Biodegradation was monitored over 28 days by determining the total petroleum hydrocarbon content of the soil and total hydrocarbon degrading bacteria. The results showed that combination of brewery waste effluents amendment and bioventing technique was the most effective, reaching up to 91.5% of diesel removal from contaminated soil; with the brewery waste effluents amendment (biostimulation-bioaugmentation, the percentage of diesel oil removal was 78.7%; with bioventing, diesel oil percentage degradation was 61.7% and the natural bioattenuation technique resulted in diesel oil removal percentage be not higher than 40%. Also, the total hydrocarbon-degrading bacteria (THDB count in all the treatments increased throughout the remediation period. The highest bacterial growth was observed for combined brewery waste effluents amendment with bioventing treatment strategy. A first-order kinetic model was fitted to the biodegradation data to evaluate the biodegradation rate and the corresponding half-life time was estimated. The model revealed that diesel oil contaminated-soil microcosms under combined brewery waste effluents amendment with bioventing treatment strategy had higher biodegradation rate constants, k as well as lower half-life times, t1/2 than other remediation systems. This study showed that the microbial consortium, organic solids, nitrogen and phosphorus present in the brewery waste effluents proved to be efficient as potential biostimulation-bioaugmentation agents for bioremediation processes of soils contaminated with diesel oil

  17. BIODEGRADATION OF DIESEL OIL IN SOIL AND ITS ENHANCEMENT BY APPLICATION OF BIOVENTING AND AMENDMENT WITH BREWERY WASTE EFFLUENTS AS BIOSTIMULATION-BIOAUGMENTATION AGENTS

    OpenAIRE

    Samuel Agarry; Ganiyu K. Latinwo

    2015-01-01

    The purpose of this study is to investigate and evaluate the effects of natural bioattenuation, bioventing, and brewery waste effluents amendment as biostimulation-bioaugmentation agent on biodegradation of diesel oil in unsaturated soil. A microcosm system was constructed consisting of five plastic buckets containing 1 kg of soil, artificially contaminated or spiked with 10% w/w of diesel oil. Biodegradation was monitored over 28 days by determining the total petroleum hydrocarbon content of...

  18. Pilot-scale studies of soil vapor extraction and bioventing for remediation of a gasoline spill at Cameron Station, Alexandria, Virginia

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, W.; Joss, C.J.; Martino, L.E. [and others

    1994-07-01

    Approximately 10,000 gal of spilled gasoline and unknown amounts Of trichloroethylene and benzene were discovered at the US Army`s Cameron Station facility. Because the base is to be closed and turned over to the city of Alexandria in 1995, the Army sought the most rapid and cost-effective means of spill remediation. At the request of the Baltimore District of the US Army Corps of Engineers, Argonne conducted a pilot-scale study to determine the feasibility of vapor extraction and bioventing for resolving remediation problems and to critique a private firm`s vapor-extraction design. Argonne staff, working with academic and private-sector participants, designed and implemented a new systems approach to sampling, analysis and risk assessment. The US Geological Survey`s AIRFLOW model was adapted for the study to simulate the performance of possible remediation designs. A commercial vapor-extraction machine was used to remove nearly 500 gal of gasoline from Argonne-installed horizontal wells. By incorporating numerous design comments from the Argonne project team, field personnel improved the system`s performance. Argonne staff also determined that bioventing stimulated indigenous bacteria to bioremediate the gasoline spin. The Corps of Engineers will use Argonne`s pilot-study approach to evaluate remediation systems at field operation sites in several states.

  19. Evaluación de las técnicas de atenuación natural, bioventing, bioaumentación y bioaumentación- bioventing, para la biodegradación de diésel en un suelo arenoso, en experimentos en columna

    Directory of Open Access Journals (Sweden)

    Angélica María Muskus Morales

    2013-08-01

    Full Text Available El presente estudio fue desarrollado dentro del convenio de cooperación institucional realizado entre laUniversidad Pontifi cia Bolivariana, Seccional Bucaramanga y el Instituto Colombiano de Petróleos – ICP, con el fi nde dar solución a una problemática que se presenta en las zonas de manejo de hidrocarburos, donde se evidenciansuelos arenosos contaminados con diésel hasta concentraciones del 6% y a una profundidad máxima de 80 cm.Para el desarrollo metodológico se contaminó un suelo artifi cialmente con diésel para evaluar las técnicas deBioventing, Atenuación Natural, Bioaumentación y Bioventing-Bioaumentación, utilizando montajes en columnas.Se defi nieron los parámetros de diseño y seguimiento como dimensiones de las columnas, caudal de entrada,concentración de diésel, oxígeno disuelto y crecimiento bacteriano; para la bioaumentación se inoculó el suelocon un consorcio bacteriano producido por el ICP. Se realizaron los montajes experimentales por triplicado y secontroló el proceso durante cuatro meses. Los resultados obtenidos mostraron que en la técnica de Bioventingse obtuvieron porcentajes de remoción de diésel hasta del 97%. Con la técnica de Bioventing-Bioaumentación sealcanzaron porcentajes de remoción hasta del 75% y con las técnicas de Atenuación Natural y Bioaumentación,los porcentajes de remoción no superaron el 48%. El estudio mostró que el consorcio bacteriano utilizado yevaluado mediante las técnicas de Bioaumentación y Bioventing-Bioaumentación, no potencializó la efi cienciade los procesos de biorremediación del suelo arenoso contaminado con diésel.

  20. 生物通风过程中的甲苯运移及生物降解%Flow,transport and biodegradation of toluene during bioventing

    Institute of Scientific and Technical Information of China (English)

    隋红; 徐世民; 李鑫钢; 姜斌; 黄国强

    2004-01-01

    Bioventing is conducted on one-dimensional soil columns.A numerical model is developed for simulating the mass exchange,advective and dispersive transport and biodegradation of toluene.The model parameters are estimated independently through laboratory batch experiments,or from literature.Simulations are found to provide reasonable agreement with experimental data.Experimental results show that toluene removal due to biodegradation is more important at the later stage.The total cleanup time when NAPL(non-aqueous phase liquid)phase exists was twice more than that without NAPL.Sensitivity analysis of parameters suggests that model predictions are mainly dependent on mass transfer coefficient and microbial parameters,such as the half-saturation coefficient and maximum specific substrate utilization rate.

  1. Report on bioventing of petroleum contaminated soils at 108-3C: Active extraction and passive injection (barometric pumping) of a gaseous nutrient

    Energy Technology Data Exchange (ETDEWEB)

    Kastner, J.R.; Lombard, K.; Radway, J. [and others

    1997-05-01

    A bioventing system was constructed with horizontal extraction wells and vertical injection wells in an area which had previously been excavated and then backfilled. Initial in-situ respiration rates (air addition only) suggest that hydrocarbon degradation may be nutrient limited. The rate of TPH degradation was maximum (0.8-1.2 mg/kg/day) between 10-15 ft (bgs), but dropped to essentially zero 30 ft (bgs) within the contaminated zone (even though previous analysis at this depth indicated a TPH concentration of 3800 ppm). Analysis of the soil at 17 ft showed that NO{sub 3} and PO{sub 4} were below detection limits (0.5 ppm), indicating that nutrient limitation may be occurring. Nitrate levels were highest at 10 ft (bgs), correlating with the highest respiration rates. However, phosphate levels were at/or below detection levels throughout tile site (indicating possible PO{sub 4} limitation). Viable cells increased from 3 x 10{sup 6} cfu/g at 3 ft (bgs) to 1 x 10{sup 7} cfu/g at 10 ft (bgs) and remained relatively constant down to 17 ft. Cell numbers in the control area were significantly lower than in the contaminated zone (4.5 x 10{sup 3}). Gas phase nutrients (triethlyphosphate and nitrous oxide) will be injected to see if the hydrocarbon degradation rate can be increased.

  2. A numerical model (MISER) for the simulation of coupled physical, chemical and biological processes in soil vapor extraction and bioventing systems

    Science.gov (United States)

    Rathfelder, Klaus M.; Lang, John R.; Abriola, Linda M.

    2000-05-01

    The efficiency and effectiveness of soil vapor extraction (SVE) and bioventing (BV) systems for remediation of unsaturated zone soils is controlled by a complex combination of physical, chemical and biological factors. The Michigan soil vapor extraction remediation (MISER) model, a two-dimensional numerical simulator, is developed to advance our ability to investigate the performance of field scale SVE and BV systems by integrating processes of multiphase flow, multicomponent compositional transport with nonequilibrium interphase mass transfer, and aerobic biodegradation. Subsequent to the model presentation, example simulations of single well SVE and BV systems are used to illustrate the interplay between physical, chemical and biological processes and their potential influence on remediation efficiency and the pathways of contaminant removal. Simulations of SVE reveal that removal efficiency is controlled primarily by the ability to engineer gas flow through regions of organic liquid contaminated soil and by interphase mass transfer limitations. Biodegradation is found to play a minor role in mass removal for the examined SVE scenarios. Simulations of BV systems suggest that the effective supply of oxygen may not be the sole criterion for efficient BV performance. The efficiency and contaminant removal pathways in these systems can be significantly influenced by interdependent dynamics involving biological growth factors, interphase mass transfer rates, and air injection rates. Simulation results emphasize the need for the continued refinement and validation of predictive interphase mass transfer models applicable under a variety of conditions and for the continued elucidation and quantification of microbial processes under unsaturated field conditions.

  3. 生物通风技术修复挥发性有机污染土壤研究进展%Review on Bio-venting for VOCs-contaminated Soils

    Institute of Scientific and Technical Information of China (English)

    刘沙沙; 董家华; 陈志良; 彭晓春; 吴彦瑜; 杨兵

    2012-01-01

    生物通风法作为物理处理方法与生物处理方法相结合的一种土壤原位修复方法,因具有高效、处理费用和尾气处理成本低等特点而对挥发性有机物(Volatile Organic Compounds)污染土壤的治理具有广阔的应用前景。本文概述了生物通风系统的原理、适用范围、优点,并对生物通风的国内外研究现状进行了阐述,包括现场应用、实验室研究、模型模拟研究(非生物过程和生物降解过程模拟)及影响因素(土壤理化性状、污染物因素及微生物因素),提出了生物通风技术存在的问题及需要作的进一步研究。%Bio-venting is an in-situ remediation technique combined with physical treatment and biological treatment for volatile organic compounds polluted soils.It has broad application prospects in soil contamination caused by volatile organic compounds due to its high-performance,low treatment cost and tail gas treatment cost.In this paper,the principle,applied range,advantages,studies of bio-venting in home and abroad were summarized,including the applications in fields,laboratory research,simulation study(non-biological process and biodegradation process simulation),effect factors(the physical and chemical characteristics of the soil,contamination concentrations and microorganisms).In addition,the problems and the further research about bio-venting were raised.

  4. 生物通风修复甲苯污染土壤过程中挥发和生物降解模拟研究%Modeling for Volatilization and Bioremediation of Toluene-contaminated Soil by Bioventing

    Institute of Scientific and Technical Information of China (English)

    隋红; 李鑫钢

    2011-01-01

    A two-dimensional numerical model is developed to simulate the flow, transport and biodegradation of toluene during bioventing (BV) processes in the unsaturated zones. The simulation for a single well BV system is used to illustrate the effect of air injection rate on remediation efficiency. The air is injected into the vadose zone to create a positive pressure. Simulation results show that air injection rate is a primary parameter governing thedispersal, redistribution and surface loss of contaminant. At injection rates of 81.504 m3.d-1 (Run 1 ) and 407.52 m3d-1(Run 2), the total removed mass of toluene is 169.14 kg and 170.59 kg respectively. Ratios of volatilization to biodegradation in Run I and Run 2 are 0.57: I and 0.89: 1, respectively, indicating that lower air injection rate enhances the biodegradation efficiency greatly. Air injection rate should be optimized to meet oxygen demand and to minimize the operational cost.

  5. Simulation of remediation of multiple organic contaminants system by bioventing%生物通风修复多种有机污染物体系的模拟分析

    Institute of Scientific and Technical Information of China (English)

    隋红; 李鑫钢; 姜斌; 黄国强

    2007-01-01

    针对多污染物体系的生物通风修复过程,对生物通风(bioventing, BV)操作中的空气注入方式,单井修复还是多井修复及生物降解作用用BIOVENT软件进行了模拟,系统研究了各种操作条件对修复效果的影响.模拟研究结果表明:BV修复现场采用间歇注入的操作方式,其处理效果与连续注入方式相似,且可减小操作费用;在受污染区域小的现场采用单井修复较为合适,而当受污染区域远大于单井影响半径时,应采用多井修复才能够达到较好修复效果;BV修复前期宜使用较大空气速率来加快挥发性有机污染物的挥发速率,后期则宜采用较小空气速率以充分利用微生物降解作用去除土壤中残留污染物.

  6. Soil column simulation experiment of remediating soil contaminated by diesel using bioventing technology%生物通风技术修复柴油污染土壤的土柱模拟实验

    Institute of Scientific and Technical Information of China (English)

    杨金凤; 陈鸿汉; 王春艳; 杨正礼

    2012-01-01

    Bioventing is an in situ forced oxidative soil remediation technology which combines soil vapor extraction with biodegradation.It has broad application prospects of soil contamination caused by underground storage tank leakage.In this paper,soil column experiment,which was used to simulate diesel contamination,was conducted.The law of balance distribution of residual TPH at different times and the change of diesel quantity in soil at different depths,together with total diesel quantity of the whole column were analyzed.The results showed that:(1) The profile distribution difference of residual TPH was influenced largerly by the initial loading conditions of soil column.(2) The diesel in soil was removed mainly by volatilization and biological degradation for the column which the balance distribution curves of residual TPH was bimodal.(3) Volatilization was mainly influenced by pore volume number during soil venting and soil moisture content,and gravity was mainly influenced by initial diesel concentration,soil moisture content and the ratio of carbon,nitrogen and phosphate.In addition to venting mode,the other factors affect the biodegradation.(4) For the soil column 8 and 11,which the initial diesel concentration were higher and the soil moisture content were both less,the biodegradation was the most significant and the removal effect of diesel in soil column was the best.The results could provide a theoretical basis for the enhancement of bioventing process.%生物通风技术是将土壤气相抽提和生物降解结合起来的原位强迫氧化降解方法,对于修复因地下储油罐泄漏引起的土壤污染具有广阔的应用前景。通过室内土柱模拟柴油泄漏污染土壤,分析了不同历时残余总石油烃(total pe-troleum hydrocarbon,TPH)的平衡分布规律以及土壤中不同深度柴油量、总柴油量的变化。结果表明:(1)各柱残余TPH剖面分布差异的原因受土柱的初始

  7. Study on attenuation of diesel oil and influencing factors during remediation of contaminated soil by enhancing bioventing%强化生物通风修复过程中柴油衰减规律及其影响因素研究

    Institute of Scientific and Technical Information of China (English)

    杨金凤; 陈鸿汉; 王春艳; 刘菲

    2009-01-01

    Enhancing bioventing technology has great application prospects for remediating soil contamination caused by leaking underground storage tanks.In this study indoor soil column experiment was conducted.Natural attenuation of diesel oil in leaking contamination soil and the course of enhancing bioventing were analyzed from the viewpoint of the changes of total petroleum hydrocarbon(TPH)in soil column profile with sampiing time and degradation pattern.The results showed that the shape of residual TPH distribution curves and the location of the peak concentration were directly affected by initial diesel concentration in each column during natural attenuation and enhancing bioventing.Early in the process of natural attenuation(about 1 month),when diesel concentration in soil was 5000~40000 mg oil/kg soil,the changes of TPH in the whole column were mainly influenced by gravity migration.When diesel concentration in soil was less than or equal to 5 000 mg oil/kg soil,the changes of TPH were not only influenced by gravity migration,but also biodegradation.Approximately 2 months'venting later,extraction was prominent to maintain stable changes of the diesel concentration on the top of soil column.%强化生物通风技术对于修复因地下储油罐泄漏引起的土壤污染具有很大的应用前景.通过室内土柱模拟柴油泄漏污染土壤,从土柱中总石油烃(total petroleum hydrocarbon,TPH)剖面分布随时间的变化及降解模式角度,分析了其自然衰减和强化生物通风过程.结果表明:初始柴油浓度直接影响着各柱在自然衰减和强化生物通风过程中柱内的残余TPH平衡分布曲线的形状和浓度峰值位置;在前期自然衰减过程中(约1个月),当土壤中的柴油浓度为5000~40000 mg油/kg土时,整个柱内TPH变化的主要原因是重力扩散迁移的结果;当土壤中的柴油浓度≤5000 mg油/kg土时,其TPH的变化不仅是重力扩散迁移作用的结果,生物

  8. Soil vapor extraction and bioventing: Applications, limitations, and future research directions

    Science.gov (United States)

    Rathfelder, K.; Lang, J. R.; Abriola, L. M.

    1995-07-01

    Soil vapor extraction (SVE) has evolved over the past decade as an attractive in situ remediation method for unsaturated soils contaminated with volatile organic compounds (VOCs). SVE involves the generation of air flow through the pores of the contaminated soil to induce transfer of VOCs to the air stream. Air flow is established by pumping from vadose zone wells through which contaminant vapors are collected and transported above ground where they are treated, if required, and discharged to the atmosphere. The popularity of SVE technologies stems from their proven effectiveness for removing large quantities of VOCs from the soil, their cost competitiveness, and their relatively simple non-intrusive implementation. Widespread field application of SVE has occurred following the success of early laboratory and field scale feasibility studies [Texas Research Institute, 1980, 1984; Thornton and Wootan, 1982; Marley and Hoag, 1984; Crow et al., 1985, 1987]. As many as 18% of Superfund sites employ SVE remediation technologies [Travis and Macinnis, 1992] and numerous articles and reports have documented the application of SVE [e.g. Hutzler et al., 1989; Downey and Elliott, 1990; U.S. EPA, 1991; Sanderson et al, 1993; Gerbasi and Menoli, 1994; McCann et al., 1994;].

  9. BIOVENTING OF CHLORINATED SOLVENTS FOR GROUND-WATER CLEANUP THROUGH BIOREMEDIATION

    Science.gov (United States)

    Chlorinated solvents such as tetrachloroethylene, trichloroethylene, carbon tetrachloride, chloroform, 1,2-dichloroethane, and dichloromethane (methylene chloride) can exist in contaminated subsurface material as (1) the neat oil, (2) a component of a mixed oily waste, (3) a solu...

  10. VAPOR PHASE TREATMENT OF PCE IN A SOIL COLUMN BY LAB-SCALE ANAEROBIC BIOVENTING

    Science.gov (United States)

    Microbial destruction of highly chlorinated organic compounds must be initiated by anaerobic followed by aerobic dechlorination. In-situ dechlorination of vadose zone soil contaminated with these compounds requires, among other factors, the establishment of highly reductive anaer...

  11. REMEDIATION OF A MAJOR JET FUEL SPILL BY BIOSLURPER AND NATURAL BIOVENTING TECHNOLOGY ON AN ISLAND AIR BASE

    Science.gov (United States)

    The Indian Ocean island of Diego Garcia has served as a base for B-52 bombers. In 1991 an underground transfer pipeline fracture was discovered after a spill exceeding 200,000 gallons occurred. The hydrogeology is fresh water at less than ten feet down overlying more dense salt...

  12. Study on Removing Toluene by Bioventing%生物通风技术去除土壤中甲苯

    Institute of Scientific and Technical Information of China (English)

    隋红; 徐世民; 李鑫钢; 段云霞

    2003-01-01

    用生物通风技术来修复土壤中有害的有机污染物,试验研究结果显示:通风流量为20mL/min时,挥发去除的甲苯与生物降解去除的比例约为1.5∶1.在土柱通风操作的226h期间,共有96.68%的甲苯被去除,同时产生了128.13mg的CO2,生物降解所去除的甲苯约为初始加入甲苯的42%~49%.

  13. 石油污染土壤的生物通风修复%BIOVENTING REMEDIATION OF SOIL POLLUTED BY OIL

    Institute of Scientific and Technical Information of China (English)

    张峰; 薛晓虎

    2008-01-01

    生物通风法作为物理处理方法与生物处理方法相结合的一种土壤原位修复方法,对于修复石油污染土壤的土层功能,维护土壤生态环境等具有较大的应用前景.概述了生物通风修复方法的设计、优越性、影响生物通风修复效果的因素以及强化生物通风的手段,针对目前生物通风技术在国内外的研究进展,提出需要在现场应用研究以及描述生物通风过程的数学模型方面作进一步研究.

  14. 甲苯在渗流区的生物通风去除模拟%The simulation of removal of toluene by bioventing in the vadose zone

    Institute of Scientific and Technical Information of China (English)

    隋红; 李鑫钢; 姜斌; 段云霞

    2004-01-01

    建立了数学模型来描述生物通风过程中渗流区土壤中甲苯的运移和生物降解过程,模型考虑了对流通量、扩散通量、相间传质和生物降解项,模型中的生物降解参数由独立间歇实验用Levenkrg-Marquardt方法确定.在实验室中用土柱实验来模拟生物通风过程,结果显示,实验数据与模型比较吻合,经过50 h后,约有98%的甲苯已被去除.利用土柱尾气中甲苯实验数据和质量衡算式计算可得:挥发去除的甲苯占初始加入甲苯的53.78%,生物降解去除的甲苯为42.92%,土壤中残余甲苯浓度为2.56mg·kg-1.

  15. 生物通风修复含石油污染物土壤过程%REMEDIATION OF UNSATURATED SOIL CONTAINING PETROLEUM CONTAMINANTS BY BIOVENTING

    Institute of Scientific and Technical Information of China (English)

    隋红; 姜斌; 黄国强; 段云霞; 李鑫钢

    2004-01-01

    以苯、甲苯和对二甲苯(BTX)为模拟污染物,研究了生物通风原位土壤修复方法去除土壤中石油污染物的效果.用一维生物通风土柱实验和控制实验对比了有生物降解和无生物降解土柱中BTX的去除情况.在通风后期,控制实验中发现了很长的拖尾阶段,污染物不能进一步被有效去除,而生物通风土柱中由于生物降解作用可使土壤中污染物残留浓度更小,修复效率更高.根据实验数据估算得到生物通风过程中苯、甲苯及对二甲苯的生物降解贡献率分别为17.8%, 30.0% 和 32.3%.还用间歇实验探讨了多组分污染物之间的相互影响作用,发现甲苯的降解能够促进对二甲苯和苯的降解,而对二甲苯的存在则增加了甲苯和苯的降解滞后期.

  16. COMPARISON OF FIELD AEROBIC BIODEGRADATION RATES TO LABORATORY

    Science.gov (United States)

    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...

  17. Remediation of crude oil-contaminated soil by bioventing and composting technology%生物通风堆肥法修复原油污染土壤的实验研究

    Institute of Scientific and Technical Information of China (English)

    毛丽华; 刘菲; 马振民; 何江涛

    2009-01-01

    通过模拟实验考察了生物通风堆肥方法修复吉林油田原油污染土壤的效果,探讨了石油污染物去除的途径和作用机制.实验结果表明:向原油污染的土壤中添加生物有机肥接种、采用生物通风堆肥法进行修复,效果较好.当原油污染土壤的含油量为7.00×104mg·kg-1时.经过40d处理,原油的去除率达45%以上,最大生物降解速率常数达到了0.0333 d-1,半衰期仅为20.82d.生物降解是污染物去除的主要途径,挥发去除的油低于土壤初始含油量的0.1%.在油污土:生物有机肥(干重)以8:2、7:3和5:5三个不同比例混合的实验中,以7:3比例混合时污染物的去除最彻底,完全生物降解率占总去除率的比例约为17%.原油组分含量的变化证实了原油生物降解的发生.原油的生物降解去除率与生物降解产生的CO2存在线性关系.污染物生物降解的速率和程度与微生物的数量和活性关系密切.

  18. The evolution of bioventing remediation for petroleum-contaminated soils%土壤石油污染物生物通风修复的研究进展

    Institute of Scientific and Technical Information of China (English)

    隋红; 茹旭; 黄国强; 李鑫钢

    2003-01-01

    生物通风是一种去污效果好、操作费用低的土壤原位修复技术.文章概述了生物通风系统的结构、设计目的、适用范围和优缺点,详细论述了生物通风的国内外研究现状,包括现场应用、影响因素和强化技术及理论研究,并展望了生物通风在我国的应用前景.

  19. Orthogonal Analysis of the Influencing Factors During Remediating Diesel Contaminated Soil by Enhancing Bioventing%强化生物通风修复柴油污染土壤影响因素的正交实验

    Institute of Scientific and Technical Information of China (English)

    王春艳; 陈鸿汉; 杨金凤; 刘菲

    2009-01-01

    生物通风是继SVE后又一项主要的生物修复技术,在石油污染土壤修复中拥有广阔的前景.为寻求最佳修复效果的最优组合,采用生物通风修复柴油污染土壤的正交土柱实验,对影响生物通风修复效果的5个主要因素(污染强度、土壤含水率、C:N:P、通风的孔隙体积数、通风方式)进行了定量化.结果表明,利用强化生物通风可以在柴油污染土壤的治理中取得较好的效果;方差分析各因素均无显著性影响;极差分析得到影响强化生物通风柴油去除效果的最主要因素为土壤含水率、污染强度,次主要因素为C:N:P、通风的孔隙体积数,而通风方式对去除率的影响很小;在实验的不同阶段有些因素的最优水平有不同程度的改变,总体来说各因素的最佳水平分别为:土壤含水率为4.88%,污染强度为40000mg·kg-1,C:N:P为100:20:1,通风的孔隙体积数为4,而通风方式的两种水平对去除率的影响相差不大.

  20. Influences of Ventilation Method on Bioventing Effectiveness for a Diesel-contaminated Soil%通风方式对柴油污染土壤生物通风修复效果的影响研究

    Institute of Scientific and Technical Information of China (English)

    刘沙沙; 徐玉新; 董家华; 陈志良; 彭晓春

    2013-01-01

    生物通风法被广泛应用于不饱和土壤中挥发性有机物的去除,具有高效、费用低等优点.以黄壤为实验土样,柴油为污染物,采用室内一维土柱实验模拟生物通风过程,研究了抽提和注入两种通风方式下柴油的去除效果及规律.结果表明,两种通风方式的去除规律大致相同,抽提方式的去除速度要比注入快,但最终去除率仅比注入高2.28%;每日通风前后及通风过程中测定的土柱总出气口中总挥发性有机化合物(TVOC)值的变化规律也基本相同,只是通风后TVOC值相对较高;在一天8h的通风过程中,每隔1,2,3h测定的TVOC值波动变化的程度为TVOC1h>TVOC2h>TVOC3h;土壤中有效磷和速效氮的含量与柴油生物降解效率密切相关.

  1. 生物通风体系中的土壤环境研究及微生物分析%STUDY ON SOIL ENVIRONMENT AND ABORIGINAL ANIMALCULE CONDITION OF BIOVENTING SYSTEM

    Institute of Scientific and Technical Information of China (English)

    杨乐巍; 李鑫钢; 黄国强; 吴丹; 王卓先

    2007-01-01

    对生物通风体系进行土壤环境研究及微生物分析.采用土柱法测得现场土壤的空气有效渗透率为ki=4.8446×10-12m2,通过气液两相流动试验得到气-液相对渗透率曲线;试验期间土壤平均含水量为0.2689g,pH值在7.0-8.5之间;微生物含量在注入污染物及营养盐后先下降后回升,驯化后期细菌密度达107(个·g-1干土)数量级.试验结果表明,该土壤环境适合使用生物通风法进行油污染修复.

  2. 石油污染土壤生物通风修复及其强化技术%Remediation and enhanced technology of bioventing in petroleum contaminated soils

    Institute of Scientific and Technical Information of China (English)

    沈铁孟; 黄国强; 李凌; 李鑫钢; 徐世民

    2002-01-01

    处理石油污染土壤的诸多方法中,生物通风法是一种很有效的治理方法.本文通过对生物通风法的技术、经济分析,得出该方法的可行性.另外,还介绍了生物通风的强化技术.

  3. Simulation Experiment for Remediating Diesel Fuel Contaminated Soil by Bio-venting Technology%生物通风法修复柴油污染土壤模拟实验研究

    Institute of Scientific and Technical Information of China (English)

    刘沙沙; 陈志良; 董家华; 彭晓春; 徐玉新

    2014-01-01

    通过生物通风技术修复不同柴油浓度污染土壤的土柱模拟实验,研究了各土柱中土壤总石油烃(totalpetroleum hydrocarbon,TPH)的去除规律,并对影响柴油去除效果的因素进行了分析,结果表明:①经过3个月的生物通风后,初始柴油浓度为5(柱Ⅰ)、10(柱Ⅱ)、20(柱Ⅲ)、40(柱Ⅳ)g/kgg的土柱柴油去除率为Ⅱ>Ⅰ>Ⅳ>Ⅲ,柱Ⅱ的修复效果最佳,半衰期为60.05天,TPH最终去除率达65.3%;②挥发和生物降解作用影响土柱中柴油的去除,由于重力引起的向下迁移作用只对柴油在土柱中的空间分布产生影响,三者共同作用决定各土柱不同取样口柴油的去除规律;③在实验过程中,各土柱土壤pH变化不大,初始柴油浓度越高土柱水分损失率越小;有效磷和速效氮含量均有所降低,柱Ⅲ降低率最大,分别为58.27%和31.87%,柱Ⅰ最小;土柱上层土壤中的酶活性要低于下层,过氧化氢酶和脱氢酶活性均呈现出先升高后降低的趋势.实验结果为研究各土柱中柴油的生物降解规律提供了依据.

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

    Science.gov (United States)

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

  5. Alternatieve in situ bodemsaneringstechnieken; literatuuronderzoek bij het project "In Situ Biorestauratie" Asten

    NARCIS (Netherlands)

    Scheuter AJ; LBG

    1997-01-01

    Aan de hand van literatuurgegevens zijn resultaten en kosten onderzocht van praktijksaneringen waarbij de bodem doorstroomd werd met lucht. De saneringstechnieken waarbij zuurstof via de lucht aan de bodem wordt toegevoerd, zijn bodemventilatie, bodemluchtextractie, bioventing en persluchtinject

  6. BIOREMEDIATION TRAINING

    Science.gov (United States)

    Bioremediation encompasses a collection of technologies which use microbes to degrade or transform contaminants. Three technologies have an established track record of acceptable performance: aerobic bioventing for fuels; enhanced reductive dechlorination for chlorinated solvent...

  7. IN SITU BIOREMEDIATION STRATEGIES FOR ORGANIC WOOD PRESERVATIVES

    Science.gov (United States)

    Laboratory biotreatability studies evaluated the use of bioventing and biosparging plus groundwater circulation (UVB technology) for their potential abililty to treat soil and groundwater containing creosote and pentachlorophenol. Soils from two former wood-treatment facilities w...

  8. Study of Biodegradation BTX(benzene, toluene, xylene)By Contrasting Bioventing and Soil Vapor Extraction%气相抽提与生物通风技术对比研究微生物对苯、甲苯、对二甲苯(BTX)的降解

    Institute of Scientific and Technical Information of China (English)

    段云霞; 韩振为; 隋红; 李鑫钢

    2003-01-01

    土壤污染是比较广泛的一种污染.土壤中最严重的污染物是石油类物质的污染,其中苯系化合物(BTX)是最难降解的一类污染物,在治理土壤石油污染中,土壤原位修复中的土壤气相抽提法(SVE)是近年来国外常用的一种方法,随后与微生物降解相结合,产生了生物通风(BV)技术.本文通过实验计算出土壤中污染物BTX的去除作用,生物的降解率分别达到20%、34.4%和38.40%.

  9. APPLICATION STRATEGIES AND DESIGN CRITERIA FOR IN SITU BIOREMEDIATION OF SOIL AND GROUNDWATER IMPACTED BY PAHS

    Science.gov (United States)

    Biotreatability studies conducted in our laboratory used soils from two former wood-treatment facilities to evaluate the use of in situ bioventing and biosparging applications for their potential ability to remediate soil and groundwater containing creosote. The combination of ph...

  10. Soil and Sediment remediation, mechanisms, technologies and applications

    NARCIS (Netherlands)

    Lens, P.N.L.; Grotenhuis, J.T.C.; Malina, G.; Tabak, H.H.

    2005-01-01

    Technologies for the treatment of soils and sediments in-situ (landfarming, bioscreens, bioventing, nutrient injection, phytoremediation) and ex-situ (landfarming, bio-heap treatment, soil suspension reactor) will be discussed. The microbiological, process technological and socio-economical aspects

  11. Field Validation of the NUFT Code for Subsurface Remediation by Soil Vapor Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Nitao, J.J.

    2000-09-23

    Soil vapor extraction (SVE) is a widely-used method for remediation of contaminants in the unsaturated, or vadose, zone. SVE removes volatile contaminants by extracting gases from the subsurface. The pressure gradients necessary to drive gas flow are limited by at most one atmosphere of vacuum. Therefore, a common adjunct to SVE is the injection of fresh air into the subsurface at a distance from the extraction wells in order to increase overall gas pressure gradients, and, hence, flow rates. SVE has also been used for saturated zone remediation by first pumping the water table down to expose free phase contaminants. The selection of a vadose zone remediation method depends on a variety of site parameters. The type of contaminant is a major factor. Obviously, the selection of SVE as a method makes sense only for volatile contaminants since, otherwise, gas phase transport would be impossible. Bioventing is often a cost-effective candidate for contaminants that biodegrade easily in an aerobic environment, such as petroleum hydrocarbons. Bioventing shares some similarity to SVE, except that the flow rates are usually much lower. Whereas, the main goal of bioventing is to provide oxygen to the micro-organisms that break-down the contaminant; the main goal of SVE is physical removal. Biodegradation may be, for some contaminants, an important side benefit of SVE. However, bioventing and other forms of bioremediation are not considered to be effective for chlorinated vadose zone contaminants, such as trichloroethylene (TCE), which does not biodegrade readily in an aerobic environment. Soil excavation is a viable remediation method for the shallow spills where there are no existing important man-made structures. Otherwise, SVE is often the most appropriate and widely used remediation method for VOC's in the vadose zone.

  12. Monitoring of Gasoline-ethanol Degradation In Undisturbed Soil

    Science.gov (United States)

    Österreicher-Cunha, P.; Nunes, C. M. F.; Vargas, E. A.; Guimarães, J. R. D.; Costa, A.

    Environmental contamination problems are greatly emphasised nowadays because of the direct threat they represent for human health. Traditional remediation methods fre- quently present low efficiency and high costs; therefore, biological treatment is being considered as an accessible and efficient alternative for soil and water remediation. Bioventing, commonly used to remediate petroleum hydrocarbon spills, stimulates the degradation capacity of indigenous microorganisms by providing better subsur- face oxygenation. In Brazil, gasoline and ethanol are mixed (78:22 v/v); some authors indicate that despite gasoline high degradability, its degradation in subsurface is hin- dered by the presence of much more rapidly degrading ethanol. Contaminant distribu- tion and degradation in the subsurface can be monitored by several physical, chemical and microbiological methodologies. This study aims to evaluate and follow the degra- dation of a gasoline-ethanol mixture in a residual undisturbed tropical soil from Rio de Janeiro. Bioventing was used to enhance microbial degradation. Shifts in bacte- rial culturable populations due to contamination and treatment effects were followed by conventional microbiology methods. Ground Penetrating Radar (GPR) measure- ments, which consist of the emission of electro-magnetic waves into the soil, yield a visualisation of contaminant degradation because of changes in soil conductivity due to microbial action on the pollutants. Chemical analyses will measure contaminant residue in soil. Our results disclosed contamination impact as well as bioventing stim- ulation on soil culturable heterotrophic bacterial populations. This multidisciplinary approach allows for a wider evaluation of processes occurring in soil.

  13. Assisted bioremediation tests on three natural soils contaminated with benzene

    Directory of Open Access Journals (Sweden)

    Maria Manuela Carvalho

    2015-07-01

    Full Text Available Bioremediation is an attractive and useful method of remediation of soils contaminated with petroleum hydrocarbons because it is simple to maintain, applicable in large areas, is economic and enables an effective destruction of the contaminant. Usually, the autochthone microorganisms have no ability to degrade these compounds, and otherwise, the contaminated sites have inappropriate environmental conditions for microorganism’s development. These problems can be overcome by assisted bioremediation (bioaugmentation and/or biostimulation. In this study the assisted bioremediation capacity on the rehabilitation of three natural sub-soils (granite, limestone and schist contaminated with benzene was evaluated. Two different types of assisted bioremediation were used: without and with ventilation (bioventing. The bioaugmentation was held by inoculating the soil with a consortium of microorganisms collected from the protection area of crude oil storage tanks in a refinery. In unventilated trials, biostimulation was accomplished by the addition of a nutrient mineral media, while in bioventing oxygen was also added. The tests were carried out at controlled temperature of 25 ºC in stainless steel columns where the moist soil contaminated with benzene (200 mg per kg of soil occupied about 40% of the column’s volume. The processes were daily monitored in discontinued mode. Benzene concentration in the gas phase was quantified by gas chromatography (GC-FID, oxygen and carbon dioxide concentrations were monitored by respirometry. The results revealed that the three contaminated soils were remediated using both technologies, nevertheless, the bioventing showed faster rates. With this work it was proved that respirometric analysis is an appropriate instrument for monitoring the biological activity.

  14. The use of integrated sanitation procedures for decontamination of the geological environment by oil pollution

    International Nuclear Information System (INIS)

    For groundwater and soil remediation in a habitat of refining plant Slovnaft in vicinity of Vojany and in former plant Slovnaft Benatech Zilina was suggested and realized a remediation technology. This technology combine some technological methods with relative conditioned effects. Realized technology take advantage of bioventing, biosparging, pumping of ground water with biodegradation and in Vojany also stripping (for elimination of oil compounds in air was realized bio-filter). Operation results demonstrated that preventing - remediation system realized on both habitats it's possible to state, that developed groundwater and soil remediation technology was satisfactory and effective. (author)

  15. The farst paper for the control and insitu remediation of groundwater contaminated with organic contaminats%地下水有机污染控制及就地恢复技术研究进展(一)

    Institute of Scientific and Technical Information of China (English)

    钟佐燊

    2001-01-01

    本文是关于地下水有机污染控制及其就地恢复技术研究进展概况的第一篇文章,文中介绍抽出-处理系统、水力隔离系统、生物通风及曝气技术的研究进展。%The paper is first paper for the control and in situ remediation of groundwater contaminated with organic contaminants. The content of paper present advances for pump-and-treat systems,hydrodynamic isolation systems,bioventing, and air sparging.

  16. In situ remediation of petroleum hydrocarbons in the Antarctic and sub-Antarctic

    Energy Technology Data Exchange (ETDEWEB)

    Rayner, J.; Snape, I.; Ferguson, S.; Harvey, P.; Raymond, T. [Australian Government Antarctic Div., Kingston, Tasmania (Australia). Environmental Protection and Change; Mumford, K.; Stevens, G. [Melbourne Univ., Parkville, Victoria (Australia). Dept. of Chemical and Biomolecular Engineering; Walworth, J. [Arizona Univ., Tucson, AZ (United States)

    2007-07-01

    The results of 2 bioremediation experiments conducted in Antarctica were presented. The aim of the study was to improve in situ remediation techniques in cold, remote locations using tracer tests and intensive monitoring. Sampling techniques were used to assess the effectiveness of a permeable reactive barrier (PRB) at Casey Station, Antarctica. A micro-bioventing trial was conducted at Macquarie Island. The PRB was installed to prevent off-site migration of hydrocarbons and to promote the biodegradation of organic compounds. The PRB was comprised of 5 cage pallets containing 5 different treatments of granulated materials separated by 2 mm galvanized steel plates. Treatments consisted of controlled release nutrients at the front of the barrier, hydrocarbon and nutrient sorption in the middle, and excess nutrient sorption at the effluent end. Materials included zeolite, Max bac, granulated activated carbon, and sand. Water from a catchment was directed into the barriers from 2 subsurface drains. Residence times and proportion of flow were measured with a salt tracer test by analyzing the breakthrough curves at locations throughout the PRC. Tracer tests were used to assess bypass or short-circuiting of flow. The micro bioventing test at Macquarie Island was installed to provide maximum oxygenation of a shallow, water-saturated subsurface to promote the biodegradation of a 20-year old fuel spill. The effectiveness of the biovents was monitored with in-situ oxygen sensors. Water samples were collected before and after aeration. Respiration rates were estimated by stopping the aeration process and compared with laboratory studies to determine nutrient, oxygen, and moisture status. Results for the PRB tests showed that hydraulic conductivity was different in all 5 treatments. Estimates from the slopes of each residence time curve ranged from 2000 m/d to 4000 m/d. Tracer mass distribution curves ranged from 30 per cent to 15 per cent. Results of the micro bioventing study

  17. Biological Remediation of Soil: An Overview of Global Market and Available Technologies

    Science.gov (United States)

    Singh, Ajay; Kuhad, Ramesh C.; Ward, Owen P.

    Due to a wide range of industrial and agricultural activities, a high number of chemical contaminants is released into the environment, causing a significant concern regarding potential toxicity, carcinogenicity, and potential for bioaccumulation in living systems of various chemicals in soil. Although microbial activity in soil accounts for most of the degradation of organic contaminants, chemical and physical mechanisms can also provide significant transformation pathways for these compounds. The specific remediation processes that have been applied to clean up contaminated sites include natural attenuation, landfarming, biopiling or composting, contained slurry bioreactor, bioventing, soil vapor extraction, thermal desorption, incineration, soil washing and land filling (USEPA 2004).

  18. In situ bioremediation of oil pollution in the unsaturated zone

    International Nuclear Information System (INIS)

    Leakage of an underground storage tank at the Trandum Army Base caused a 20.000 liter spill of fuel oil. Several options for remediation have been evaluated. In situ bioremediation was chosen as the most cost effective and realistic method and was evaluated in detail. Preliminary laboratory studies showed that a large number of hydrocarbon degrading micro-organism are present and that good degradation rates can be obtained with the addition of a nitrogen and phosphorus source. Since July 1991 a full scale bioventing installation has been in operation. The preliminary monitoring results give an indication of biological activity. 8 refs., 6 figs., 2 tabs

  19. In-situ biodegradation of ethanolamine in low permeability soils

    International Nuclear Information System (INIS)

    A research program to investigate whether ethanolamine is susceptible to biodegradation is described. The project was undertaken at a former Edmonton area gas plant site to demonstrate in-situ site remediation techniques. A horizontal well was drilled at a depth of four metres below ground surface and hydraulically fractured to increase permeability of the glacial till soils. A sand propant was used to prevent the subsequent closure of the water-based slurry used in fracturing the soil, with phosphoric acid added to provide a source of phospate to stimulate bacterial growth. A network of monitoring wells was installed along the horizontal wells to monitor bacterial respiration. Field test results showed oxygen depletion and carbon dioxide production. Bioventing was restricted as a result of unexpectedly high water levels, but in a subsequent dewatering bioventing program the ethanolamine levels in groundwater extracted from the monitoring wells showed an overall decline in concentration. There were no changes in ammonia levels. Since ammonia is a breakdown product of amines its increase in the groundwater would have provided positive proof of biodegradation. However, the fact that there was no change, is not taken as an indication of the total absence of biodegradation. Rather, it is suspected that the concentration of the ammonia in the groundwater is at a level that it exerts a a toxic influence on the soil bacteria, thus preventing additional degradation. 14 refs., 4 tabs.7 figs

  20. Bioremediation at a petroleum refinery

    International Nuclear Information System (INIS)

    This paper presents a summary of three projects at the Mobil Refinery in Torrance, California where bioremediation technologies were successfully employed for the remediation of hydrocarbon contaminated soil. The three projects represent variations of implementation of bioremediation, both in-situ and ex-situ. Soil from all of the projects was considered non-hazardous designated waste under the California Code of Regulations, Title 23, section 2522. The projects were permitted and cleanup requirements were defined with the Los Angeles Regional Water Quality Control Board. In all of the projects, different methods were used for supplying water, oxygen, and nutrients to the hydrocarbon degrading bacteria to stimulate growth. The Stormwater Retention Basin Project utilized in-situ mechanical mixing of soils to supply solid nutrients and oxygen, and a self-propelled irrigation system to supply water. The Tank Farm Lake project used an in-situ active bioventing technology to introduce oxygen, moisture, and vapor phase nutrients. The Tank 1340X247 project was an ex-situ bioventing remediation project using a drip irrigation system to supply water and dissolved nutrients, and a vapor extraction system to provide oxygen

  1. Bioremediation of diethylhexyl phthalate contaminated soil: a feasibility study in slurry- and solid-phase reactors.

    Science.gov (United States)

    Di Gennaro, P; Collina, E; Franzetti, A; Lasagni, M; Luridiana, A; Pitea, D; Bestetti, G

    2005-01-01

    The aim of the research was to verify the possibility of applying bioremediation as a treatment strategy on a poly(vinyl chloride) (PVC) manufacturing site in the north of Italy contaminated by diethylhexyl phthalate (DEHP) at a concentration of 5.51 mg/g of dry soil. Biodegradation kinetic experiments with DEHP contaminated soil samples were performed in both slurry- and solid-phase systems. The slurry-phase results showed that the cultural conditions, such as N and P concentrations and the addition of a selected DEHP degrading strain, increased the natural DEHP degradation rate. On the basis of these data, experiments to simulate bioventing on contaminated soil columns were performed. The DEHP concentration reached 0.63 mg/g of dry soil in 76 days (89% of degradation). A kinetic equation was developed to fit the experimental data and to predict the concentration of contaminant after treatment. The data obtained are encouraging for a future in situ application of the bioventing technology.

  2. Toluene removal from sandy soils via in situ technologies with an emphasis on factors influencing soil vapor extraction.

    Science.gov (United States)

    Amin, Mohammad Mehdi; Hatamipour, Mohammad Sadegh; Momenbeik, Fariborz; Nourmoradi, Heshmatollah; Farhadkhani, Marzieh; Mohammadi-Moghadam, Fazel

    2014-01-01

    The integration of bioventing (BV) and soil vapor extraction (SVE) appears to be an effective combination method for soil decontamination. This paper serves two main purposes: it evaluates the effects of soil water content (SWC) and air flow rate on SVE and it investigates the transition regime between BV and SVE for toluene removal from sandy soils. 96 hours after air injection, more than 97% removal efficiency was achieved in all five experiments (carried out for SVE) including 5, 10, and 15% for SWC and 250 and 500 mL/min for air flow rate on SVE. The highest removal efficiency (>99.5%) of toluene was obtained by the combination of BV and SVE (AIBV: Air Injection Bioventing) after 96 h of air injection at a constant flow rate of 250 mL/min. It was found that AIBV has the highest efficiency for toluene removal from sandy soils and can remediate the vadose zone effectively to meet the soil guideline values for protection of groundwater.

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

    Science.gov (United States)

    Lahvis, Matthew A.; Baehr, Arthur L.

    1996-07-01

    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 gyr-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 gm-2yr-1 (1.45×10-3 and 1.51×10-3 gal.ft.-2yr-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.

  4. Managing soil remediation problems.

    Science.gov (United States)

    Okx, J P; Hordijk, L; Stein, A

    1996-12-01

    Soil remediation has only a short history but the problem addressed is a significant one. Cost estimates for the clean-up of contaminated sites in the European Union and the United States are in the order of magnitude of 1,400 billion ECU. Such an enormous operation deserves the best management it can get. Reliable cost estimations per contaminated site are an important prerequisite. This paper addresses the problems related to site-wise estimations.When solving soil remediation problems, we have to deal with a large number of scientific disciplines. Too often solutions are presented from the viewpoint of only one discipline. In order to benefit from the combined disciplinary knowledge and experience, we think that it is necessary to describe the interrelations between these disciplines. This can be realized by developing an adequate model of the desired process which enables to consider and evaluate the essential factors as interdependent components of the total system.The resulting model provides a binding paradigm to the contributing disciplines which will result in improved efficiency and effectivity of the decision and the cost estimation process. In the near future, we will release the "Biosparging and Bioventing Expert Support System", an expert support system for problem owners, consultants and authorities dealing with the design and operation of a biosparging and/or a bioventing system.

  5. Biological Treatment of Petroleum in Radiologically Contaminated Soil

    Energy Technology Data Exchange (ETDEWEB)

    BERRY, CHRISTOPHER

    2005-11-14

    This chapter describes ex situ bioremediation of the petroleum portion of radiologically co-contaminated soils using microorganisms isolated from a waste site and innovative bioreactor technology. Microorganisms first isolated and screened in the laboratory for bioremediation of petroleum were eventually used to treat soils in a bioreactor. The bioreactor treated soils contaminated with over 20,000 mg/kg total petroleum hydrocarbon and reduced the levels to less than 100 mg/kg in 22 months. After treatment, the soils were permanently disposed as low-level radiological waste. The petroleum and radiologically contaminated soil (PRCS) bioreactor operated using bioventing to control the supply of oxygen (air) to the soil being treated. The system treated 3.67 tons of PCRS amended with weathered compost, ammonium nitrate, fertilizer, and water. In addition, a consortium of microbes (patent pending) isolated at the Savannah River National Laboratory from a petroleum-contaminated site was added to the PRCS system. During operation, degradation of petroleum waste was accounted for through monitoring of carbon dioxide levels in the system effluent. The project demonstrated that co-contaminated soils could be successfully treated through bioventing and bioaugmentation to remove petroleum contamination to levels below 100 mg/kg while protecting workers and the environment from radiological contamination.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-12-31

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

  8. Toluene Removal from Sandy Soils via In Situ Technologies with an Emphasis on Factors Influencing Soil Vapor Extraction

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Amin

    2014-01-01

    Full Text Available The integration of bioventing (BV and soil vapor extraction (SVE appears to be an effective combination method for soil decontamination. This paper serves two main purposes: it evaluates the effects of soil water content (SWC and air flow rate on SVE and it investigates the transition regime between BV and SVE for toluene removal from sandy soils. 96 hours after air injection, more than 97% removal efficiency was achieved in all five experiments (carried out for SVE including 5, 10, and 15% for SWC and 250 and 500 mL/min for air flow rate on SVE. The highest removal efficiency (>99.5% of toluene was obtained by the combination of BV and SVE (AIBV: Air Injection Bioventing after 96 h of air injection at a constant flow rate of 250 mL/min. It was found that AIBV has the highest efficiency for toluene removal from sandy soils and can remediate the vadose zone effectively to meet the soil guideline values for protection of groundwater.

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

    Science.gov (United States)

    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.

  10. In situ vadose zone bioremediation.

    Science.gov (United States)

    Höhener, Patrick; Ponsin, Violaine

    2014-06-01

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

  11. In situ bioremediation of nitrate and perchlorate in vadose zone soil for groundwater protection using gaseous electron donor injection technology.

    Science.gov (United States)

    Evans, Patrick J; Trute, Mary M

    2006-12-01

    When present in the vadose zone, potentially toxic nitrate and perchlorate anions can be persistent sources of groundwater contamination. Gaseous electron donor injection technology (GEDIT), an anaerobic variation of petroleum hydrocarbon bioventing, involves injecting electron donor gases, such as hydrogen or ethyl acetate, into the vadose zone, to stimulate biodegradation of nitrate and perchlorate. Laboratory microcosm studies demonstrated that hydrogen and ethanol promoted nitrate and perchlorate reduction in vadose zone soil and that moisture content was an important factor. Column studies demonstrated that transport of particular electron donors varied significantly; ethyl acetate and butyraldehyde were transported more rapidly than butyl acetate and ethanol. Nitrate removal in the column studies, up to 100%, was best promoted by ethyl acetate. Up to 39% perchlorate removal was achieved with ethanol and was limited by insufficient incubation time. The results demonstrate that GEDIT is a promising remediation technology warranting further validation.

  12. Enhancement of the microbial community biomass and diversity during air sparging bioremediation of a soil highly contaminated with kerosene and BTEX.

    Science.gov (United States)

    Kabelitz, Nadja; Machackova, Jirina; Imfeld, Gwenaël; Brennerova, Maria; Pieper, Dietmar H; Heipieper, Hermann J; Junca, Howard

    2009-03-01

    In order to obtain insights in complexity shifts taking place in natural microbial communities under strong selective pressure, soils from a former air force base in the Czech Republic, highly contaminated with jet fuel and at different stages of a bioremediation air sparging treatment, were analyzed. By tracking phospholipid fatty acids and 16S rRNA genes, a detailed monitoring of the changes in quantities and composition of the microbial communities developed at different stages of the bioventing treatment progress was performed. Depending on the length of the air sparging treatment that led to a significant reduction in the contamination level, we observed a clear shift in the soil microbial community being dominated by Pseudomonads under the harsh conditions of high aromatic contamination to a status of low aromatic concentrations, increased biomass content, and a complex composition with diverse bacterial taxonomical branches.

  13. Engineering Applications of Microbial Remediation Technology in Organic Contaminated Sites%微生物技术修复有机污染场地的工程化应用

    Institute of Scientific and Technical Information of China (English)

    李朝廷; 李建洲; 雷继雨

    2012-01-01

    综述了国内外微生物技术在有机污染场地修复中的应用,对几种有机污染场地修复技术进行了重点介绍,包括生物通风法、地下水曝气法、生物堆法、生物反应器法以及土壤耕作法的工程化应用,并对微生物修复技术今后的发展方向进行了展望.%The latest microbial remediation technology of organic contaminated site is reviewed. Several kinds of engineering applications are discussed in detail,which mainly included bioventing,air sparging,biopile,bioreactor and land farming. As well,the review discusses the future development of microbial site remediation technology.

  14. Enhancement of the microbial community biomass and diversity during air sparging bioremediation of a soil highly contaminated with kerosene and BTEX

    Energy Technology Data Exchange (ETDEWEB)

    Kabelitz, Nadja; Heipieper, Hermann J. [Helmholtz Centre for Environmental Research (UFZ), Leipzig (Germany). Dept. of Bioremediation; Machackova, Jirina [Earth Tech CZ s.r.o., Prague (Czech Republic); Imfeld, Gwenael [Helmholtz Centre for Environmental Research (UFZ), Leipzig (Germany). Dept. of Isotope Biogeochemistry; Brennerova, Maria [Czech Academy of Sciences, Prague (CZ). Inst. of Microbiology (IMIC); Pieper, Dietmar H.; Junca, Howard [Helmholtz Centre for Infection Research (HZI), Braunschweig (Germany). Biodegradation Research Group

    2009-03-15

    In order to obtain insights in complexity shifts taking place in natural microbial communities under strong selective pressure, soils from a former air force base in the Czech Republic, highly contaminated with jet fuel and at different stages of a bioremediation air sparging treatment, were analyzed. By tracking phospholipid fatty acids and 16S rRNA genes, a detailed monitoring of the changes in quantities and composition of the microbial communities developed at different stages of the bioventing treatment progress was performed. Depending on the length of the air sparging treatment that led to a significant reduction in the contamination level, we observed a clear shift in the soil microbial community being dominated by Pseudomonads under the harsh conditions of high aromatic contamination to a status of low aromatic concentrations, increased biomass content, and a complex composition with diverse bacterial taxonomical branches. (orig.)

  15. Environmental biotechnology research: an overview.

    Science.gov (United States)

    Spain, J C

    1994-05-01

    Cleanup and treatment of hazardous wastes incur major operational costs for the U.S. Air Force. Bioremediation can provide a cost-effective alternative to traditional technologies for a wide range of natural organic compounds such as jet fuel. Bioventing and natural attenuation are emerging as treatments of choice in many instances. Synthetic organic chemicals are much more resistant to biodegradation. However, recent advances in biotechnology allow the development of strains able to use nitro- and chloro-substituted organic compounds as their sole source of carbon and energy. Current basic research is focused on expanding the range of synthetic chemicals amenable to biodegradation. At the same time, development of appropriate bioreactors and models for scale up are essential for practical application of the technology.

  16. Use of environmental isotopes in organic contaminants research in groundwater systems

    International Nuclear Information System (INIS)

    The paper presents two case studies that explore the use of environmental isotopes (13Cl, 37Cl) in organic contaminants research in groundwater systems. Carbon-13 data on soil CO2 were collected at a gas plant site where the degradation of organic contaminants by bioventing is being investigated. The isotope study was done to contribute to the evaluation of biodegradation of organic contaminants, especially under field conditions where results obtained by standard techniques are not conclusive. The results show enriched δ13C values on soil CO2, in comparison with the natural gas condensate source, a by-product of gas plants. Degradation of the condensate in a controlled laboratory microcosm did not show any significant isotopic fractionation during degradation. These results suggest that preferential degradation of enriched 13C hydrocarbons is occurring during bioventing. This hypothesis is being tested under field and laboratory conditions. The isotope research on chlorinated solvents aims to evaluate the use of 37Cl and 13C as tracers to provide information about sources and transformation of chlorinated solvents in groundwater systems. Chlorine-37 and 13C data in chlorinated solvents, perchlorethylene (PCE), trichloroethylene (TCE) and 1,1,1, trichloroethane (TCA), supplied by different manufacturers range from -3.5 to +6.0 per mille for δ37Cl and from -37.2 to -23.3 per mille for δ13C. These results indicated that these compounds have a different and distinct isotopic composition, which results from the individual manufacturing practices. These results show the potential of 37Cl and 13Cl as tracers to provide information to identify source areas of chlorinated solvent plumes in groundwater. (author). 25 refs, 3 figs

  17. Bioremediation of Petroleum and Radiological Contaminated Soils at the Savannah River Site: Laboratory to Field Scale Applications

    Energy Technology Data Exchange (ETDEWEB)

    BRIGMON, ROBINL.

    2004-06-07

    In the process of Savannah River Site (SRS) operations limited amounts of waste are generated containing petroleum, and radiological contaminated soils. Currently, this combination of radiological and petroleum contaminated waste does not have an immediate disposal route and is being stored in low activity vaults. SRS developed and implemented a successful plan for clean up of the petroleum portion of the soils in situ using simple, inexpensive, bioreactor technology. Treatment in a bioreactor removes the petroleum contamination from the soil without spreading radiological contamination to the environment. This bioreactor uses the bioventing process and bioaugmentation or the addition of the select hydrocarbon degrading bacteria. Oxygen is usually the initial rate-limiting factor in the biodegradation of petroleum hydrocarbons. Using the bioventing process allowed control of the supply of nutrients and moisture based on petroleum contamination concentrations and soil type. The results of this work have proven to be a safe and cost-effective means of cleaning up low level radiological and petroleum-contaminated soil. Many of the other elements of the bioreactor design were developed or enhanced during the demonstration of a ''biopile'' to treat the soils beneath a Polish oil refinery's waste disposal lagoons. Aerobic microorganisms were isolated from the aged refinery's acidic sludge contaminated with polycyclic aromatic hydrocarbons (PAHs). Twelve hydrocarbon-degrading bacteria were isolated from the sludge. The predominant PAH degraders were tentatively identified as Achromobacter, Pseudomonas Burkholderia, and Sphingomonas spp. Several Ralstonia spp were also isolated that produce biosurfactants. Biosurfactants can enhance bioremediation by increasing the bioavailability of hydrophobic contaminants including hydrocarbons. The results indicated that the diversity of acid-tolerant PAH-degrading microorganisms in acidic oil wastes may

  18. Toxicity of vapor phase petroleum contaminants to microbial degrader communities

    International Nuclear Information System (INIS)

    Petroleum products constitute the largest quantity of synthetic organic chemical products produced in the US. They are comprised of mostly hydrocarbon constituents from many different chemical classes including alkenes, cycloalkanes, aromatic compounds, and polyaromatic hydrocarbons. Many petroleum constituents are classified as volatile organic compounds or VOCs. Petroleum products also constitute a major portion of environmental pollution. One emerging technology, with promise for applications to VOCs in subsurface soil environments, is bioventing coupled with soil vapor extraction. These technologies involve volatilization of contaminants into the soil gas phase by injection and withdrawal of air. This air movement causes enhancement of the aerobic microbial degradation of the mobilized vapors by the indigenous populations. This study investigated the effects of exposure of mixed, subsurface microbial communities to vapor phase petroleum constituents or vapors of petroleum mixtures. Soil slurries were prepared and plated onto mineral salts agar plates and exposed to vapor phase contaminants at equilibrium with pure product. Representative n-alkane, branched alkane, cycloalkane, and aromatic compounds were tested as well as petroleum product mixtures. Vapor exposure altered the numbers and morphologies of the colonies enumerated when compared to controls. However, even at high, equilibrium vapor concentrations, microbial degrader populations were not completely inhibited

  19. In situ aerobic cometabolism of chlorinated solvents: a review.

    Science.gov (United States)

    Frascari, Dario; Zanaroli, Giulio; Danko, Anthony S

    2015-01-01

    The possible approaches for in situ aerobic cometabolism of aquifers and vadose zones contaminated by chlorinated solvents are critically evaluated. Bioaugmentation of resting-cells previously grown in a fermenter and in-well addition of oxygen and growth substrate appear to be the most promising approaches for aquifer bioremediation. Other solutions involving the sparging of air lead to satisfactory pollutant removals, but must be integrated by the extraction and subsequent treatment of vapors to avoid the dispersion of volatile chlorinated solvents in the atmosphere. Cometabolic bioventing is the only possible approach for the aerobic cometabolic bioremediation of the vadose zone. The examined studies indicate that in situ aerobic cometabolism leads to the biodegradation of a wide range of chlorinated solvents within remediation times that vary between 1 and 17 months. Numerous studies include a simulation of the experimental field data. The modeling of the process attained a high reliability, and represents a crucial tool for the elaboration of field data obtained in pilot tests and for the design of the full-scale systems. Further research is needed to attain higher concentrations of chlorinated solvent degrading microbes and more reliable cost estimates. Lastly, a procedure for the design of full-scale in situ aerobic cometabolic bioremediation processes is proposed. PMID:25306537

  20. Assessment of Canadian Regulations and Remediation Methods for Diesel Oil Contaminated Soils

    Directory of Open Access Journals (Sweden)

    D. G. Rushton

    2007-01-01

    Full Text Available Diesel fuel released into the environment can contaminate ground water, degrade potable water supplies and cause the collapse of fisheries. They are toxic to both animals and humans and can affect the liver, lungs, kidneys, and nervous system leading to cancer as well as immunological and reproductive effects. The objectives of this study were to review current Canadian regulations pertaining to diesel fuel and to evaluate the current remediation methods using five criteria: efficiency, applicability, cost, time and cleanliness. PAHs are deemed toxic under the Canadian Environmental Protection Act but no standards have been set for PAHs in diesel. The Canadian Council of Ministers of the Environment (CCME has developed Canada-Wide Standards for Petroleum Hydrocarbons in Soil (CWS PHCS while the Atlantic PIRI has implemented a Risk Based Corrective Action (RBCA for the Atlantic region. The remediation methods included soil washing, landfilling, incineration, thermal desorption, radio frequency heating, chemical addition, landfarming, biopiling, composting, bioventing, liquid delivery and bioreactors. The bioreactors studied included: static bed, continuous mix, horizontal drum, fungal compost, slurry-phase, DITS, biofilters and packed bed bioreactors. The results showed that the biological methods were more effective than nonbiological ones and the bioreactors scored the highest among the biological methods. Eight criteria were then used for the evaluation of bioreactors: efficiency, time, cost, maintenance, simplicity, release of VOCs to the atmosphere, containment of contaminants and control of operating parameters The results showed that the continuous mix bioreactor was the most effective system.

  1. An integrated approach to risk-based remediation of a former bulk fuel storage facility adjacent a marine environment

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, L.; Hers, I. [Golder Associates Ltd., Vancouver, BC (Canada)

    2006-07-01

    An integrated approach to risk-based remediation of a former bulk fuel storage facility adjacent to a marine environment was discussed. The presentation provided an introduction and illustration to the site location and history, located close to Skagway, Alaska and northwestern British Columbia. The site investigation and conceptual model were also presented. The remedial approach was also described with reference to a risk-based action approach, remedial objectives, soil vapour extraction (SVE)-bioventing, and air sparging-biosparging. The objectives were to minimize potential exposure to aquatic receptors by minimizing non-aqueous phase liquids (NAPL) mobility and dissolved transport of petroleum hydrocarbons. Groundwater modeling to assess the attenuation rate and to determine remedial targets was also discussed. Model validation and results of groundwater modeling as well as remediation system details and performance were then provided. It was determined that significant attenuation is occurring and that effective mass removal and concentrations have been decreasing over time. It was demonstrated that risk-based remedial goals and hydrogeology can change with land use/development. tabs., figs.

  2. Part 2: A field study of enhanced remediation of Toluene in the vadose zone using a nutrient solution

    Science.gov (United States)

    Tindall, J.A.; Weeks, E.P.; Friedel, M.

    2005-01-01

    The objective of this study was to test the effectiveness of a nitrate-rich nutrient solution and hydrogen peroxide (H2O2) to enhance in-situ microbial remediation of toluene in the unsaturated zone. Three sand-filled plots were tested in three phases (each phase lasting approximately 2 weeks). During the control phase, toluene was applied uniformly via sprinkler irrigation. Passive remediation was allowed to occur during this phase. A modified Hoagland nutrient solution, concentrated in 150 L of water, was tested during the second phase. The final phase involved addition of 230 moles of H2O2 in 150 L of water to increase the available oxygen needed for aerobic biodegradation. During the first phase, measured toluene concentrations in soil gas were reduced from 120 ppm to 25 ppm in 14 days. After the addition of nutrients during the second phase, concentrations were reduced from 90 ppm to about 8 ppm within 14 days, and for the third phase (H 2O2), toluene concentrations were about 1 ppm after only 5 days. Initial results suggest that this method could be an effective means of remediating a contaminated site, directly after a BTEX spill, without the intrusiveness and high cost of other abatement technologies such as bioventing or soil-vapor extraction. However, further tests need to be completed to determine the effect of each of the BTEX components. ?? Springer 2005.

  3. Assessment and remediation of a historical pipeline release : tools, techniques and technologies applied to in-situ/ex-situ soil and groundwater remediation

    Energy Technology Data Exchange (ETDEWEB)

    Reid, N. [EBA Engineering Consultants Ltd., Calgary, AB (Canada); Kohlsmith, B. [Kinder Morgan Canada Inc., Calgary, AB (Canada)

    2008-07-01

    Tools, techniques, and technologies applied to in-situ/ex-situ soil and groundwater remediation were presented as part of an assessment and remediation of a historical pipeline release. The presentation discussed the initial assessment, as well as a discussion of remediation of hydrophobic soils, re-assessment, site specific criteria, a remediation trial involving bioventing and chemical oxidation, and a full scale remediation. The pipeline release occurred in the summer of 1977. The event was followed by a complete surface remediation with a significant amount of topsoil being removed and replaced. In 2004, a landowner complained of poor crop growth in four patches near the area of the historical spill. An initial assessment was undertaken and several photographs were presented. It was concluded that a comprehensive assessment set the base for a careful staged approach to the remediation of the site including the establishment of site specific criteria. The process was made possible with a high level of communication between all stakeholders. In addition, the most appropriate solution for the site was realized. figs.

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

    Science.gov (United States)

    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.

  5. Remediation in Situ of Hydrocarbons by Combined Treatment in a Contaminated Alluvial Soil due to an Accidental Spill of LNAPL

    Directory of Open Access Journals (Sweden)

    Ettore Trulli

    2016-10-01

    Full Text Available Soil contamination represents an environmental issue which has become extremely important in the last decades due to the diffusion of industrial activities. Accidents during transport of dangerous materials and fuels may cause severe pollution. The present paper describes the criteria of the actions which were operated to remediate the potential risk and observed negative effects on groundwater and soil originating from an accidental spill of diesel fuel from a tank truck. With the aim to evaluate the quality of the involved environmental matrices in the “emergency” phase, in the following “safety” operation and during the remediation action, a specific survey on hydrocarbons, light and heavy, was carried out in the sand deposits soil. Elaboration of collected data allows us to observe the movement of pollutants in the unsaturated soil. The remediation action was finalized to improve the groundwater and soil quality. The former was treated by a so called “pump and treat” system coupled with air sparging. A train of three different technologies was applied to the unsaturated soil in a sequential process: soil vapour extraction, bioventing and enhanced bioremediation. Results showed that the application of sequential remediation treatments allowed us to obtain a state of quality in unsaturated soil and groundwater as required by Italian law.

  6. Enhanced Remediation of Toluene in the Vadose Zone via a Nitrate-Rich Nutrient Solution: Field Study

    Science.gov (United States)

    Tindall, J. A.; Friedel, M. J.

    2003-12-01

    The objective of this study was to test the effectiveness of nitrate-rich nutrient solutions and hydrogen peroxide (H202) to enhance in-situ microbial remediation of toluene. Three sand filled plots (2 m2 surface area and 1.5 meters deep) were tested in three phases (each phase lasting approximately 2 weeks). During each phase, toluene (21.6 mol as an emulsion in 50L of water) was applied uniformly via sprinkler irrigation. Passive remediation was allowed to occur during the first (control) phase. A nutrient solution (modified Hoagland), concentrated in 40L of water, was tested during the second phase. The final phase involved addition of 230 moles of H202 in 50L of water to increase the available oxygen needed for aerobic biodegradation. During the first phase, toluene concentrations in soil gas were reduced from 120 ppm to 25 ppm in 14 days. After the addition of nutrients during the second phase, concentrations were reduced from 90 ppm to about 8 ppm within 14 days, and for the third phase (H202), toluene concentrations were about 1 ppm after only five days. Initial results suggest that this method could be an effective means of remediating a contaminated site, directly after a BTEX spill, without the intrusiveness and high cost of other abatement technologies such as bioventing and soil vapor extraction. However, further tests need to be completed to determine the effect of each of the BTEX components.

  7. Remediation of DNAPLs in Low Permeability Soils. Innovative Technology Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2000-09-01

    Dense, non-aqueous phase liquid (DNAPL) compounds like trichloroethene (TCE) and perchloroethene (PCE) are prevalent at U. S. Department of Energy (DOE), other government, and industrial sites. Their widespread presence in low permeability media (LPM) poses severe challenges for assessment of their behavior and implementation of effective remediation technologies. Most remedial methods that involve fluid flow perform poorly in LPM. Hydraulic fracturing can improve the performance of remediation methods such as vapor extraction, free-product recovery, soil flushing, steam stripping, bioremediation, bioventing, and air sparging in LPM by enhancing formation permeability through the creation of fractures filled with high-permeability materials, such as sand. Hydraulic fracturing can improve the performance of other remediation methods such as oxidation, reductive dechlorination, and bioaugmentation by enhancing delivery of reactive agents to the subsurface. Hydraulic fractures are typically created using a 2-in. steel casing and a drive point pushed into the subsurface by a pneumatic hammer. Hydraulic fracturing has been widely used for more than 50 years to stimulate the yield of wells recovering oil from rock at great depth and has recently been shown to stimulate the yield of wells recovering contaminated liquids and vapors from LPM at shallow depths. Hydraulic fracturing is an enabling technology for improving the performance of some remedial methods and is a key element in the implementation of other methods. This document contains information on the above-mentioned technology, including description, applicability, cost, and performance data.

  8. Contaminated soil remediation and quality assurance; Pilaantuneen maan kunnostaminen ja laadunvarmistus

    Energy Technology Data Exchange (ETDEWEB)

    Sarkkila, J.; Mroueh, U.M.; Leino-Forsman, H.

    2004-07-01

    The aim of contaminated soil remediation quality assurance is to carry out remediation activities according to plans. Besides the design work the appropriate implementation of the quality assurance covers source data and investigation methods as well as the requirements for documentation. Contaminated soil characterization and the selection of the most suitable remediation method is made with the help of various sampling and analysis methods. There are different kinds of requirements to the sampling plan depending on the type of remediation project. Quality assurance is taken into account in sampling, in sample handling and analysis as well as in the reporting of results. The most common unsaturated zone remediation methods used in Finland are introduced in this guide. These methods include excavation (as part of remediation), encapsulating, stabilization, thermal desorption, soil washing, composting, soil vapor extraction and bioventing. The methods are introduced on a general level with emphasis on their technical implementation and feasibility as well as on the eventual material requirements. Harmful environmental impacts of the methods must be identified and prevented. In order to monitor the remediation process, various chemical and physical quality assurance measurements are performed. Additionally the work safety issues related to remediation methods must be taken into account and proper documentation must be prepared. (orig.)

  9. @@%轻质油污染土壤的原位修复技术现场试验

    Institute of Scientific and Technical Information of China (English)

    李巨峰; 张坤峰; 王明勇; 赵杰; 许德刚

    2014-01-01

    石油烃污染土壤具有生态风险高、治理难度大、治理成本高等特点,技术经济性优异的原位修复方法及装备开发已成为现阶段石油环境工程领域的研究热点.文章针对汽油、柴油等轻质油品(Light Petroleum-Hydrocarbons,LPHs)污染的土壤,设计出1套复合了土壤真空抽吸(Soil Vacuum Extraction,SVE)与生物通风(Bioventing,BV)功能的撬装式原位修复技术设备样机,并对某轻质油污染土壤进行了现场修复试验.在6个月的修复周期内,现场土壤中平均VOCs浓度由823.7 mg/L降至51.0 mg/L,修复效率平均达到80%以上,可为我国规模化实施LPHs污染土壤修复提供技术支持和应用依据.

  10. In situ petroleum hydrocarbon bioremediation in the Canadian Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Greer, C.; Bell, T.; Lee, K.; Delisle, S.; Kovanen, D.; Craig, D.; Juck, D. [National Research Council of Canada, Montreal, PQ (Canada). Biotechnology Research Inst.

    2010-07-01

    This presentation reported on the in-situ bioremediation of diesel contaminated soils at the Canadian Forces Station CFS-Alert, in the Arctic. The soil was amended with monoammonium phosphate (MAP). The operation was designed to take place in a 2 month period during the brief thaw season. This presentation described the installation of the bioventing stacks, the turning of soil, and the application of an oxygen release compound (ORC) at the surface of the permafrost. A significant decrease in petroleum hydrocarbons (PC) was noted over 2 months. The effect of MAP amendment was a slight decrease in biomass in the pristine environment and a significant increase in biomass in the contaminated environment. The alkB gene was found to be important in the biodegradation of alkanes. Stable isotope probing (SIP) was used to identify active organisms. This bioremediation study showed that even in harsh Arctic climates, soils that are moderately contaminated with petroleum hydrocarbons can be remediated effectively and economically via biodegradation. tabs., figs.

  11. Potential of preliminary test methods to predict biodegradation performance of petroleum hydrocarbons in soil.

    Science.gov (United States)

    Aichberger, H; Hasinger, Marion; Braun, Rudolf; Loibner, Andreas P

    2005-03-01

    Preliminary tests at different scales such as degradation experiments (laboratory) in shaking flasks, soil columns and lysimeters as well as in situ respiration tests (field) were performed with soil from two hydrocarbon contaminated sites. Tests have been evaluated in terms of their potential to provide information on feasibility, degradation rates and residual concentration of bioremediation in the vadose zone. Sample size, costs and duration increased with experimental scale in the order shaking flasks - soil columns - lysimeter - in situ respiration tests, only time demand of respiration tests was relatively low. First-order rate constants observed in degradation experiments exhibited significant differences between both, different experimental sizes and different soils. Rates were in line with type and history of contamination at the sites, but somewhat overestimated field rates particularly in small scale experiments. All laboratory experiments allowed an estimation of residual concentrations after remediation. In situ respiration tests were found to be an appropriate pre-testing and monitoring tool for bioventing although residual concentrations cannot be predicted from in situ respiration tests. Moreover, this method does not account for potential limitations that might hamper biodegradation in the longer term but only reflects the actual degradation potential when the test is performed.

  12. Development of a correlation for aqueous-vapor phase mass transfer in porous media

    Science.gov (United States)

    Szatkowski, Andrew; Imhoff, Paul T.; Miller, Cass T.

    1995-03-01

    In many situations vapor-phase extraction procedures (e.g., soil venting, air sparging, and bioventing) may be suitable methods for remediating porous media contaminated by volatile organic compounds. This has led to increased study of operative processes in these systems, including aqueous-vapor phase mass transfer. Past work has shown the importance of the flow regime on this process, but a quantitative estimate of mass-transfer coefficients is lacking, especially for systems not confounded by uncertainties involving interfacial area between the phases. An experimental investigation was conducted to isolate the resistance to aqueous-vapor phase mass transfer at the phase boundary, using an ideal porous medium system. Mass-transfer coefficients were measured for toluene for a wide range of Reynolds numbers. An empirical model was fit to the data in dimensionless form. The mass-transfer model was coupled with an available interfacial area model, yielding a dimensionless expression for the mass-transfer rate coefficient. This expression was used to compare results from this work to three other experimental studies reported in the literature. These comparisons showed that for experiments where infiltrating water flowed uniformly within the porous medium, the predicted mass-transfer coefficients were within a factor of 5 of the measured coefficients. Mass transfer was significantly slower than the rate predicted, using the results from this work, in experiments where infiltrating water flowed nonuniformly.

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

    Science.gov (United States)

    Li, Dong X.

    1999-02-01

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

  14. In situ aerobic cometabolism of chlorinated solvents: a review.

    Science.gov (United States)

    Frascari, Dario; Zanaroli, Giulio; Danko, Anthony S

    2015-01-01

    The possible approaches for in situ aerobic cometabolism of aquifers and vadose zones contaminated by chlorinated solvents are critically evaluated. Bioaugmentation of resting-cells previously grown in a fermenter and in-well addition of oxygen and growth substrate appear to be the most promising approaches for aquifer bioremediation. Other solutions involving the sparging of air lead to satisfactory pollutant removals, but must be integrated by the extraction and subsequent treatment of vapors to avoid the dispersion of volatile chlorinated solvents in the atmosphere. Cometabolic bioventing is the only possible approach for the aerobic cometabolic bioremediation of the vadose zone. The examined studies indicate that in situ aerobic cometabolism leads to the biodegradation of a wide range of chlorinated solvents within remediation times that vary between 1 and 17 months. Numerous studies include a simulation of the experimental field data. The modeling of the process attained a high reliability, and represents a crucial tool for the elaboration of field data obtained in pilot tests and for the design of the full-scale systems. Further research is needed to attain higher concentrations of chlorinated solvent degrading microbes and more reliable cost estimates. Lastly, a procedure for the design of full-scale in situ aerobic cometabolic bioremediation processes is proposed.

  15. Bioremediation of an area contaminated by a fuel spill.

    Science.gov (United States)

    Vallejo, B; Izquierdo, A; Blasco, R; Pérez del Campo, P; Luque de Castro, M D

    2001-06-01

    In order to decontaminate a large area of restricted access contaminated by a fuel spill, laboratory and field studies were developed in two steps: (a) monitoring of the laboratory experiment on bacterial growth under aerobic and anaerobic conditions with and without addition of nutrients; and (b) use of the best conditions obtained in (a) for the decontamination of the soil. A hydraulic barrier was installed both to clean the aquifer and to avoid migration of hydrocarbons as a consequence of their solution in the groundwater and subsequent displacement. The objective was to create an ideal environment for the treatment of the affected area that favoured the growth of the indigenous bacteria (Pseudomonas and Arthrobacter) that biodegrade the hydrocarbons. Monitoring of the changes in the total concentration of petroleum hydrocarbons in the soil subjected to bacterial action was performed by gas chromatography. In a field study, the progress of biodegradation of hydrocarbons was evaluated in situ by changes in subsurface CO2/O2 levels by means of an analyser equipped with an infrared detector. Biostimulation and oxygen were the most influential factors for the biodegradation of the hydrocarbons. The use of bioventing of the soil was shown as an excellent technology to promote in situ bioremediation of the polluted area.

  16. Effect of liquid distribution on gas-water phase mass transfer in an unsaturated sand during infiltration

    Science.gov (United States)

    Imhoff, Paul T.; Jaffé, Peter R.

    1994-09-01

    Gas-water phase mass transfer was examined in a homogeneous sand with both the gas and water phase mobile: water was infiltrated from the top of the sand column while benzene-laden air flowed upward from the bottom. Mass-transfer limitations for this situation may be important for applications of bioventing, where water and nutrients are added at the ground surface simultaneously with induced air movement to carry oxygen and volatile organics to microbial populations. Gas- and water-phase samples indicate that gas-water phase mass transfer was sufficiently fast that equilibrium between gas and water phases was achieved at all sampling locations within the porous medium. Lower-bound estimates for the gas-water mass-transfer rate coefficient show that mass transfer was at least 10-40 times larger than predictions made from an empirical model developed for gas-water phase mass transfer in an identical porous medium. A water-phase tracer test demonstrates that water flow was much more uniform in this study than in those earlier experiments, which is a likely explanation for the differing rates of gas-water phase mass transfer. It is hypothesized that the liquid distribution in previous laboratory experiments was less uniform because of preferential flow paths due to wetting front instabilities. Gas-water phase mass-transfer rate coefficients reported in this investigation are for an ideal situation of uniform water infiltration: mass-transfer rates in field soils are expected to be significantly smaller.

  17. Near surface soil vapor clusters for monitoring emissions of volatile organic compounds from soils.

    Science.gov (United States)

    Ergas, S J; Hinlein, E S; Reyes, P O; Ostendorf, D W; Tehrany, J P

    2000-01-01

    The overall objective of this research was to develop and test a method of determining emission rates of volatile organic compounds (VOCs) and other gases from soil surfaces. Soil vapor clusters (SVCs) were designed as a low dead volume, robust sampling system to obtain vertically resolved profiles of soil gas contaminant concentrations in the near surface zone. The concentration profiles, when combined with a mathematical model of porous media mass transport, were used to calculate the contaminant flux from the soil surface. Initial experiments were conducted using a mesoscale soil remediation system under a range of experimental conditions. Helium was used as a tracer and trichloroethene was used as a model VOC. Flux estimations using the SVCs were within 25% of independent surface flux estimates and were comparable to measurements made using a surface isolation flux chamber (SIFC). In addition, method detection limits for the SVC were an order of magnitude lower than detection limits with the SIFC. Field trials, conducted with the SVCs at a bioventing site, indicated that the SVC method could be easily used in the field to estimate fugitive VOC emission rates. Major advantages of the SVC method were its low detection limits, lack of required auxiliary equipment, and ability to obtain real-time estimates of fugitive VOC emission rates.

  18. Technical and economic feasibility of soil flushing with non-ionic surfactant to remediate gas well condensate

    Energy Technology Data Exchange (ETDEWEB)

    Felske, D.; Morton, P.R. [EBA Engineering Consultants Ltd., Calgary, AB (Canada)

    2005-07-01

    The results of a feasibility study to assess the technical and economic viability of remediating condensate-impacted soils surrounding a main gas pipeline in northern Alberta by in situ flushing with non-ionic surfactant were presented. A commercially available non-ionic surfactant was evaluated for its solubility increasing properties as an economic means of solubilizing soil-bonded condensate. An injection-recovery well configuration was situated within the condensate spill pathway and was selected for a series of inter-well tests using surfactant injection and its recovery from a nearby pumped recovery well. Sodium bromide was used as a conservative tracer to assist in the selection of surfactant and solubilized hydrocarbon samples from the recovery well for laboratory analysis. Surfactant, hydrocarbon and tracer breakthrough curves were plotted for the recovered groundwater. Results enabled the quantification of surfactant effects on recovered groundwater. Findings demonstrated that the non-ionic surfactant achieved a significant solubilization and soil remediation of condensate at a more economic rate than bioventing, biosparging or soil vapour extraction when considered over the projected time, and attained all regulatory soil and groundwater quality remediation objectives.

  19. Bioremediation of oil-contaminated sites

    Energy Technology Data Exchange (ETDEWEB)

    Balba, T. [Conestoga-Rovers and Associates, Calgary, AB (Canada)

    2003-07-01

    One of the most prevalent contaminants in subsurface soil and groundwater are petroleum hydrocarbons. This paper presented bioremediation of petroleum hydrocarbons as one of the most promising treatment technologies. Petroleum hydrocarbons are categorized into four simple fractions: saturates, aromatics, resins, and asphaltenes. Bioremediation refers to the treatment process whereby contaminants are metabolized into less toxic or nontoxic compounds by naturally occurring organisms. The various strategies include: use of constitutive enzymes, enzyme induction, co-metabolism, transfer of plasmids coding for certain metabolic pathways, and production of biosurfactants to enhance bioavailability of hydrophobic compounds. Three case studies were presented: (1) bioremediation of heavy oils in soil at a locomotive maintenance yard in California, involving a multi-step laboratory treatability study followed by a field demonstration achieving up to 94 per cent removal of TPH in less than 16 weeks, (2) bioremediation of light oils in soil at an oil refinery in Germany where a dual process was applied (excavation and in-situ treatment), achieving an 84 per cent reduction within 24 weeks, and (3) bioremediation of oil-contaminated desert soil in Kuwait which involved landfarming, composting piles, and bioventing soil piles, achieving an 80 per cent reduction within 12 months. 7 refs., 1 tab., 3 figs.

  20. Design and analysis of a SVE system in a shallow water table application

    International Nuclear Information System (INIS)

    Cummins Southeastern Power, Inc. (CSPI) operates a diesel engine repair facility in Hialeah Gardens, FL. Parsons Engineering Science, Inc. (Parsons ES) was retained to design a treatment system to remediate soil and hydrocarbons beneath the CSPI service building. Soil vapor extraction (SVE) followed by bioventing was selected as the most appropriate and cost effective approach. These activities were completed as part of CSPI's overall environmental program, which includes cleanup of any contamination that is encountered at their facilities and continual implementation of new measures to prevent future contamination from occurring. This paper presents a complete case history outlining the unique technical challenges associated with the CSPI site conditions. The methods utilized during completion and analysis of the pilot test are discussed and a description of how the pilot data was utilized for completion of the full-scale design is included. The paper presents the empirical analysis method which was developed during this design and shows how it can be applied to other SVE remediation applications

  1. Surfactant-aided recovery/in situ bioremediation for oil-contaminated sites

    International Nuclear Information System (INIS)

    Bioremediation has been the most commonly used method way for in situ cleaning of soils contaminated with low-volatility petroleum products such as diesel oil. However, whatever the process (bioventing, bioleaching, etc.), it is a time-consuming technique that may be efficiency limited by both accessibility and too high concentrations of contaminants. A currently developed process aims at quickly recovering part of the residual oil in the vadose and capillary zones by surfactant flushing, then activating in situ biodegradation of the remaining oil in the presence of the same or other surfactants. The process has been tested in laboratory columns and in an experimental pool, located at the Institut Franco-Allemand de Recherche sur l'Environnement (IFARE) in Strasbourg, France. Laboratory column studies were carried out to fit physico-chemical and hydraulic parameters of the process to the field conditions. The possibility of recovering more than 80% of the oil in the flushing step was shown. For the biodegradation step, forced aeration as a mode of oxygen supply, coupled with nutrient injection aided by surfactants, was tested

  2. Integrated technologies for expedited soil and groundwater remediation

    International Nuclear Information System (INIS)

    A fast-track and economic approach was necessary to meet the needs of a property transfer agreement and to minimize impact to future usage of a site in the Los Angeles Basin. Woodward-Clyde responded by implementing site investigation, remedial action plan preparation for soil and groundwater, and selection and installation of remedial alternatives in an aggressive schedule of overlapped tasks. Assessment of soil and groundwater was conducted at the site, followed by design and construction of remediation systems. This phase of activity was completed within 2 years. Soil and groundwater were found to be impacted by chlorinated solvents and petroleum hydrocarbons. A vapor extraction system (2,000 scfm capacity) was installed for soil remediation, and an innovative air sparging system was installed for cost effective groundwater cleanup. A bioventing system was also applied in selected areas. The vapor extraction wellfield consists of 26 extraction and monitoring well points, with multiple screened casings. The air sparging wellfield consists of 32 sparging wells with a designed maximum flow of 400 scfm. The systems began operation in 1993, and have resulted in the estimated removal of approximately 30,000 pounds of contaminants, or about 90% of the estimated mass in place. The combined vapor extraction/air sparging system is expected to reduce the time for on-site groundwater remediation from 1/3 to 1/6 the time when compared to the conventional pump and treat method for groundwater remediation

  3. Design and implementation of a highly integrated and automated in situ bioremediation system for petroleum hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Dey, J.C.; Rosenwinkel, P. [Resource Control Corp., Rancocas, NJ (United States); Norris, R.D. [Eckenfelder, Inc., Nashville, TN (United States)

    1996-12-31

    The proposed sale of an industrial property required that an environmental investigation be conducted as part of the property transfer agreement. The investigation revealed petroleum hydrocarbon compounds (PHCs) in the subsurface. Light nonaqueous phase liquids (LNAPLs) varsol (a gasoline like solvent), gasoline, and fuel oil were found across a three (3) acre area and were present as liquid phase PHCs, as dissolved phase PHCs, and as adsorbed phase PHCs in both saturated and unsaturated soils. Fuel oil was largely present in the unsaturated soils. Fuel oil was largely present in the unsaturated soils. Varsol represented the majority of the PHCs present. The presence of liquid phase PHCs suggested that any remedial action incorporate free phase recovery. The volatility of varsol and gasoline and the biodegradability of the PHCs present in the subsurface suggested that bioremediation, air sparging, and soil vapor extraction/bioventing were appropriate technologies for incorporation in a remedy. The imminent conversion of the impacted area to a retail facility required that any long term remedy be unobtrusive and require minimum activity across much of the impacted area. In the following sections the site investigation, selection and testing of remedial technologies, and design and implementation of an integrated and automated remedial system is discussed.

  4. Vertical radar profiles for the calibration of unsaturated flow models under dynamic water table conditions

    Science.gov (United States)

    Cassiani, G.; Gallotti, L.; Ventura, V.; Andreotti, G.

    2003-04-01

    The identification of flow and transport characteristics in the vadose zone is a fundamental step towards understanding the dynamics of contaminated sites and the resulting risk of groundwater pollution. Borehole radar has gained popularity for the monitoring of moisture content changes, thanks to its apparent simplicity and its high resolution characteristics. However, cross-hole radar requires closely spaced (a few meters), plastic-cased boreholes, that are rarely available as a standard feature in sites of practical interest. Unlike cross-hole applications, Vertical Radar Profiles (VRP) require only one borehole, with practical and financial benefits. High-resolution, time-lapse VRPs have been acquired at a crude oil contaminated site in Trecate, Northern Italy, on a few existing boreholes originally developed for remediation via bioventing. The dynamic water table conditions, with yearly oscillations of roughly 5 m from 6 to 11 m bgl, offers a good opportunity to observe via VRP a field scale drainage-imbibition process. Arrival time inversion has been carried out using a regularized tomographic algorithm, in order to overcome the noise introduced by first arrival picking. Interpretation of the vertical profiles in terms of moisture content has been based on standard models (Topp et al., 1980; Roth et al., 1990). The sedimentary sequence manifests itself as a cyclic pattern in moisture content over most of the profiles. We performed preliminary Richards' equation simulations with time varying later table boundary conditions, in order to estimate the unsaturated flow parameters, and the results have been compared with laboratory evidence from cores.

  5. Ecofunctional enzymes of microbial communities in ground water.

    Science.gov (United States)

    Fliermans, C B; Franck, M M; Hazen, T C; Gorden, R W

    1997-07-01

    Biolog technology was initially developed as a rapid, broad spectrum method for the biochemical identification of clinical microorganisms. Demand and creative application of this technology has resulted in the development of Biolog plates for Gram-negative and Gram-positive bacteria, for yeast and Lactobacillus sp. Microbial ecologists have extended the use of these plates from the identification of pure culture isolates to a tool for quantifying the metabolic patterns of mixed cultures, consortia and entire microbial communities. Patterns that develop on Biolog microplates are a result of the oxidation of the substrates by microorganisms in the inoculum and the subsequent reduction of the tetrazolium dye to form a color in response to detectable reactions. Depending upon the functional enzymes present in the isolate or community one of a possible 4 x 10(28) patterns can be expressed. The patterns were used to distinguish the physiological ecology of various microbial communities present in remediated groundwater. The data indicate that one can observe differences in the microbial community among treatments of bioventing, 1% and 4% methane injection, and pulse injection of air, methane and nutrients both between and among wells. The investigation indicates that Biolog technology is a useful parameter to measure the physiological response of the microbial community to perturbation and allows one to design enhancement techniques to further the degradation of selected recalcitrant and toxic chemicals. Further it allows one to evaluate the recovery of the microbial subsurface ecosystem after the perturbations have ceased. We propose the term 'ecofunctional enzymes' (EFE) as the most descriptive and useful term for the Biolog plate patterns generated by microbial communities. We offer this designation and provide ecological application in an attempt to standardize the terminology for this relatively new and unique technology.

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

    Science.gov (United States)

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

    2006-12-01

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

  7. Application Evaluation of Air-Sparging and Aerobic Bioremediation in PAM(Physical Aquifer Model) with Advanced and Integrated Module

    Science.gov (United States)

    Hong, U.; Ko, J.; Park, S.; Kim, Y.; Kwon, S.; Ha, J.; Lim, J.; Han, K.

    2010-12-01

    It is generally difficult for a single process to remediate contaminated soil and groundwater contaminated with various organic compounds such as total petroleum hydrocarbon (TPH), benzene, toluene, ethylbenzene, xylene (BTEX), chlorinated aliphatic hydrocarbons (CAHs) because those contaminants show different chemical properties in two phases (e.g. soil and groundwater). Therefore, it is necessary to design an in-situ remediation system which can remove various contaminants simultaneously. For the purpose, we constructed integrated well module which can apply several remediation process such as air sparging, soil vapor extraction, and bioventing. The advanced integrated module consisted of three main parts such as head, body, and end cap. First of all, head part has three 3.6-cm-diameter stainless lines and can simultaneously inject air or extract NAPL, respectively. Secondly, body part has two 10-cm-height screen intervals with 100-mesh stainless inserts for unsaturated and smear zone. Lastly, we constructed three different sizes of end caps for injection and extraction from a saturated zone. We assumed that the integrated module can play bioremediation, air sparging, cometabolic sparging, chemical oxidation. In this study, we examined application of air sparing and aerobic bioremediation of toluene in Physical Aquifer Model (PAM) with an integrated well module. During air sparging experiments, toluene concentration decreased by injection of air. In addition, we accomplished bioremediation experiment to evaluate removal of toluene by indigenous microbes in PAM with continuous air injection. From the two experiments result, we confirmed that air sparging and aerobic bioremediation processes can be simultaneously carried out by an intergrated well module.

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

    Science.gov (United States)

    Woodward, R.; Sloan, R.

    2003-04-01

    precautions used for gasoline and other fuel hydrocarbons. Indeed specific physical properties of ethers and alcohols expedite their treatment by traditional remediation methods of pump and treat, soil vapor extraction and bioventing.

  9. Soil Contamination and Remediation Strategies. Current research and future challenge

    Science.gov (United States)

    Petruzzelli, G.

    2012-04-01

    Soil contamination: the heritage of industrial development Contamination is only a part of a whole set of soil degradation processes, but it is one of paramount importance since soil pollution greatly influences the quality of water, food and human health. Soil contamination has been identified as an important issue for action in the European strategy for soil protection, it has been estimated that 3.5 million of sites are potentially contaminated in Europe. Contaminated soils have been essentially discovered in industrial sites landfills and energy production plants, but accumulation of heavy metals and organic compounds can be found also in agricultural land . Remediation strategies. from incineration to bioremediation The assessment of soil contamination is followed by remedial action. The remediation of contaminated soils started using consolidates technologies (incineration inertization etc.) previously employed in waste treatment,. This has contributed to consider a contaminated soil as an hazardous waste. This rough approximation was unfortunately transferred in many legislations and on this basis soil knowledge have been used only marginally in the clean up procedures. For many years soil quality has been identified by a value of concentration of a contaminant and excavation and landfill disposal of soil has been largely used. In the last years the knowledge of remediation technology has rapidly grown, at present many treatment processes appear to be really feasible at field scale, and soil remediation is now based on risk assessment procedures. Innovative technologies, largely dependent on soil properties, such as in situ chemical oxidation, electroremediation, bioventing, soil vapor extraction etc. have been successfully applied. Hazardous organic compounds are commonly treated by biological technologies, biorememdiation and phytoremediation, being the last partially applied also for metals. Technologies selection is no longer exclusively based on