U.S. EPA Contaminated Site Cleanup Information (CLU-IN)

U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division


Aerobic Bioremediation (Direct)


Examples of Superfund NPL Sites Using Aerobic Bioremediation Technologies

Aerobic Bioremediation of 1,2-Dichloroethane and Vinyl Chloride at Field Scale (Abstract)
Davis, G.B., B.M. Patterson, and C.D. Johnston. Journal of Contaminant Hydrology, Vol. 107 No. 1-2, p. 91-100, 2009

Aerobic bioremediation of 1,2 dichloroethane (1,2-DCA) and vinyl chloride (VC) was evaluated at field scale in a layered, silty and fine-sand anaerobic aquifer. Maximum concentrations of 1,2-DCA (2 g/L) and VC (0.75 g/L) in groundwater were within 25% and 70% of pure compound solubility, respectively. Aerobic conditions were induced by injecting air into sparging wells screened 20.5 to 21.5 m below ground (17 to 18 m below the water table). Using a cycle of 23 h of air injection followed by three days of no air injection, 50 days of air injection were accumulated over a 12-month period that included some longer periods of operational shutdown. The dissolved mass of 1,2-DCA and VC was reduced by >99% over the 590 m2 trial plot. The pH declined from nearly 11 to less than 9, and sulfate concentrations increased dramatically, suggesting the occurrence of mineral sulfide (e.g., pyrite) oxidation. Chloride and bicarbonate (aerobic biodegradation byproducts) concentration increases were used to estimate biodegradation of 300 to 1,000 kg of chlorinated hydrocarbons, although the ratio of 1,2-DCA to VC that was biodegraded remained uncertain. The aerobic biodegradation rates were greater than those previously estimated from laboratory-based studies.

Enhanced Aerobic Bioremediation of Petroleum Hydrocarbons Using PermeOx® Plus (Abstract)
Hulseapple, S.M. and S.B. LeFevre (URS Corporation, Clifton Park, NY); C. Elmendorf and P.J. Palko (Panther Technologies, Inc., Medford, NJ). The 19th Annual International Conference on Contaminated Soils, Sediments and Water, 20-23 October 2003, University of Massachusetts at Amherst. Poster presentation. Northeast Regional Environmental Health Center, Univ. of Massachusetts, Amherst. CD-ROM, 2003

A full-scale in situ enhanced bioremediation program targeted petroleum contamination at a school bus maintenance garage in Otego, NY. After the removal of the leaky USTs and contaminated soils in 1998, in situ enhanced bioremediation was proposed as a cost-effective alternative to conventional ex situ remedial methods because ongoing site use limited the available space for aboveground structures associated with conventional ex situ cleanup. PermeOx® Plus, produced by FMC Industrial Chemicals, was selected as the enhancement product. The compound provides oxygen to enhance the biodegradation of petroleum hydrocarbons through a reaction of the specialty formulation of calcium peroxide and water. In July 2002, total BTEX mass at the site was estimated at 4.7 kg. PermeOx® Plus was injected in 200 x 80 x 8-ft-deep treatment zone using a direct-push drill rig at 107 locations within the plume area. In addition, Bioblend™ M-4, a blend of petroleum-degrading bacteria and nutrients, was injected into the contaminant plume. By December 2002, total BTEX mass within the plume was reduced to 1.7 kg. A second PermeOx® Plus injection was conducted in a 140 x 70-ft area at 55 locations.

Adobe PDF LogoAerobic Bioremediation of MTBE and BTEX at a U.S. Coast Guard Facility
Hicks, P. (ARCADIS, Raleigh, NC); M.R. Pahr (ARCADIS, Raleigh, NC); J.P. Messier (USCG, Elizabeth City, NC); R. Gillespie (Regenesis, Plano, TX). The 6th International In Situ and On-Site Bioremediation Symposium, Battelle, 2001

A full-scale in situ bioremediation of dissolved methyl tert-butyl ether (MTBE) and benzene, toluene, ethylbenzene, and xylenes (BTEX) ended successfully in 2000 at the U.S. Coast Guard Support Center in Elizabeth City, NC. The goal of the project was to enhance the natural attenuation of dissolved petroleum constituents without interfering with facility operations. Aquifer oxygenation to enhance bioremediation rates was accomplished by injecting Oxygen Release Compound (ORC™) into both the source and dissolved plume areas. Post-treatment monitoring of the aquifer quality parameters indicated a substantial decrease in dissolved MTBE and BTEX concentrations. Monitoring results showed 100% reduction of the dissolved MTBE mass in both the source and plume areas. The dissolved BTEX mass decreased by 99% in the source area and 53% in the plume area following oxygenation of the aquifer. Current monitoring efforts verify that intrinsic remediation is occurring at a rate sufficient to protect downgradient receptors. Site closure has been obtained from the North Carolina Department of Environment and Natural Resources, Division of Environmental Management.

Enhanced Aerobic Bioremediation of a Gasohol Release in a Fractured Bedrock Aquifer (Abstract)
Heaston, M.S., L.L. Hartig, M. Robinson, and D.S. Woodward. Remediation Journal, Vol. 20 No. 2, p. 45-59, Spring 2010

In January 2005, a gasoline tanker carrying ~8,500 gallons of gasohol (gasoline containing 10% ethanol) overturned and caught fire in the front yard of a residence. Emergency response crews attended to the accident, extinguished the fire, and recovered residual gasoline on the ground surface. Soil affected by the release was then removed and disposed of off site, and free-phase gasohol was recovered using a combination of vacuum recovery, pumping, and bailing to the extent practicable. Following free product recovery efforts, a feasibility evaluation was completed and was followed by a successful pilot test of biosparging, which led to the installation of a full-scale biosparging system. After 21 months of full-scale operation, contaminant concentrations within the heart of the plume decreased dramatically—in most cases, to below applicable cleanup standards. Despite the complex hydrogeologic conditions and significant initial concentrations, biosparging proved to be an effective technology to remediate the gasohol release, and the authors anticipate that two to three years of biosparging (i.e., an additional 3 to 15 months of system operation) can achieve drinking-water standards.

Bioremediation of a Mineral Soil with High Contents of Clay and Organic Matter Contaminated with Herbicide 2,4-Dichloro-Phenoxyacetic Acid Using Slurry Bioreactors: Effect of Electron Acceptor and Supplementation with an Organic Carbon Source (Abstract)
Robles-Gonzalez, I. (CINVESTAV-IPN, Mexico); E. Rios-Leal; R. Ferrera-Cerrato; F. Esparza-Garcia; N. Rinderkenecht-Seijas; H.M. Poggi-Varaldo. Process Biochemistry, Vol 41 No 9, p 1951-1960, Sep 2006

The removal of 2,4-dichlorophenoxyacetic acid (2,4-D) from an agricultural mineral soil containing organic matter (4%) and clay (48%) was evaluated in lab-scale slurry bioreactors under aerobic and anaerobic (sulfate-reducing) conditions, both with and without an additional carbon source (sucrose). The soil was sterilized and spiked with 300 mg 2,4-D/kg dry matrix prior to introduction to the slurry bioreactors, both of which received bacteria (20%, v/v) acclimated to 2,4-D from aerobic and sulfate-reducing continuous complete-mix reactors. The investigators found that aerobic conditions were more favorable for the degradation of 2,4-D in terms of the overall removal efficiency (93%) compared to 25% under sulfate-reducing conditions during a 14-day treatment period, but the specific removal rate in the sulfate-reducing bioreactor was significantly higher than that in the aerobic bioreactor. This difference was attributed to the fact that the aerobic inoculum was much denser than the sulfate-reducing inoculum. Aerobic removal was not affected by the sucrose supplementation, whereas the sulfate-reducing bioreactor removed 2,4-D to a slightly greater extent with sucrose than without. Overall, the slurry bioreactor bioremediation technique achieved effective removal of the herbicide from mineral agricultural soils characterized by a fine texture and high content of organic matter.

Bioremediating PAHs and TPH at the Watervliet Arsenal (Abstract)
Talley, J.W. (USACE Waterways Experiment Station, Vicksburg, MS); K.J. Goldstein; R.G. Schaar; P.B. Hatzinger; S. Chaki; M. Senick. Bioreactor and Ex Situ Biological Treatment Technologies. Battelle Press, Columbus, OH. ISBN 1-57477-078-0. p 87-95, 1999

A study was conducted at a contaminated site within the Watervliet Arsenal in New York State to assess the feasibility of bioremediation for the treatment of soils affected by PAHs and petroleum hydrocarbons. Indigenous organisms were determined to be able to aerobically and anaerobically degrade PAHs, and a demonstration of total petroleum hydrocarbon (TPH) and PAH biodegradation in soil slurries was conducted. The Microtox bioassay was used to determine soil toxicity before and after treatment. This paper describes the protocols of the microcosm experiment and the aerobic soil column study. Although both aerobic and anaerobic PAH degraders were present at the site, aerobic processes were found to be more efficient than anaerobic processes. The soil column data indicate that in situ land farming would result in significant reductions in both PAH and TPH concentrations at the site.

As of 2008, land farming was implemented as an interim measure. For more information, see The Defense Environmental Restoration Program reportAdobe PDF Logo (2003), the Army Restoration Status and Progress reportAdobe PDF Logo (2003), and the New York State Department of Environmental Conservation web page.

Performance of Full-Scale Enhanced Reductive Dechlorination in Clay Till
Damgaard, I. , P.L. Bjerg, C.S. Jacobsen, A. Tsitonaki, H. Kerrn-Jespersen, and M.M. Broholm.
Ground Water Monitoring & Remediation 33(1):48-61(2013)

Enhanced reductive dechlorination was implemented by direct-push injection of molasses and dechlorinating bacteria at a low-permeability clay till site contaminated with chlorinated ethenes (Gl. Kongevej, Denmark ). After 4 years of remediation, the formation of degradation products, the presence of Dehalococcoides spp., and the isotope fractionation of TCE, cis-DCE, and VC demonstrated the degradation of chlorinated ethenes in the clay till matrix as well as in sand lenses, sand stringers, and fractures. Bioactive sections of up to 1.8 m had developed in the clay till matrix, while sections where degradation was restricted to narrow zones around sand lenses and stringers were also observed. An average mass reduction of 24% was estimated after 4 years of remediation. Model simulation scenarios indicate that a mass reduction of 85% can be obtained within ~50 years without further increase in the narrow reaction zones if no donor limitations occur at the site. Additional information: I. Damgaard Ph.D. thesisAdobe PDF Logo (2012); Broholm et al.Adobe PDF Logo (2012); Design Tool

Adobe PDF LogoField Demonstration of Propane Biosparging for In Situ Remediation of N-Nitrosodimethylamine (NDMA) in Groundwater
Hatzinger, P.B. and D. Lippincott.
ESTCP Project ER-200828, 205 pp, 2015

Propane gas and oxygen were added to groundwater via sparging to stimulate native microbes to biodegrade NDMA in situ at the Aerojet Superfund site in Rancho Cordova, Calif. Groundwater NDMA concentrations at the test site ranged from ~2,000 to >30,000 ng/L. The biosparging system was operated for a period of 374 days, and full rounds of sampling were conducted on 12 occasions. Data from this field test indicate that propane biosparging can be an effective approach to reduce the concentrations of NDMA in a groundwater aquifer by 3 to 4 orders of magnitude, and that concentrations in the low ng/L range can be achieved with continuous treatment. The groundwater in this region currently is captured by a groundwater extraction and treatment system, and NDMA is removed by UV irradiation. Based on a cost analysis for treatment of a shallow groundwater plume (~10-40 ft bgs) ~400 ft in width, a propane biosparge barrier was estimated to be more cost-effective for NDMA removal than pump and treat with either UV or a fluidized bed bioreactor. Additional information: ESTCP Cost and Performance ReportAdobe PDF Logo

Adobe PDF LogoBioaugmentation for Aerobic Bioremediation of RDX-Contaminated Groundwater
Michalsen, M., F. Crocker, K. Indest, C. Jung, M. Fuller, P. Hatzinger, and J. Istok.
ESTCP Project ER-201207, 264 pp, 2016

This project demonstrated an innovative application of bioaugmentation to enhance RDX biodegradation in contaminated groundwater under aerobic conditions at the Umatilla Chemical Depot (UMCD) in Umatilla, Oregon. The principal demonstration objectives were to (1) select and optimize RDX-degrading microbial cultures for use in aerobic bioaugmentation at the site; (2) compare in situ RDX biodegradation rates for aerobic bioaugmentation to those for biostimulation; and (3) quantify and compare costs of RDX remediation. Additional information: ESTCP Cost and Performance ReportAdobe PDF Logo

Adobe PDF LogoDesign and Implementation of EISB Systems for Chlorinated Compound Remediation
Harkness, M. ǀ Remediation Seminar Part 1: Effective Bioremediation of Chlorinated Solvent Sites - Avoiding Pitfalls and Maximizing Performance, 28 April, Virtual, 56 slides, 2021

This presentation provides a high-level approach to choosing and designing enhanced in situ bioremediation (EISB) systems to remediate chlorinated compound in soil and groundwater. Topics covered include when to consider EISB, types of EISB systems, selection of electron donors and injection methods, and the role of laboratory treatability and pilot studies in informing full-scale designs. Use of bioaugmentation and buffer addition and the applicability of EISB to DNAPL source areas also are addressed.

Adobe PDF LogoEffective Bioremediation of Chlorinated Solvent Sites — Avoiding Pitfalls and Maximizing Performance
Birk, G.M. ǀ Remediation Seminar Part 1: Effective Bioremediation of Chlorinated Solvent Sites - Avoiding Pitfalls and Maximizing Performance, 28 April, Virtual, 39 slides, 2021

This presentation discusses deployment of electron donors via in situ alcoholysis to overcome two of the main challenges associated with EVO injection (poor fatty acid subsurface distribution and biofouling). The reaction is accomplished in situ with a homogenized alkaline catalyst to form long-lasting and soluble electron donors. The products formed in situ travel more easily than EVO, add a pH buffer to the system and leave the system less susceptible to clogging and biofouling.

Adobe PDF LogoCost-Effective Destruction of Petroleum Hydrocarbon Contaminants With Expedited Residual Mass — Smear Zone (Lnapl) Destruction Under Anaerobic Conditions Via Biostimulation
Armstrong, K. ǀ RemTech 2020: The Remediation Technologies Symposium, virtual, 13-15 October, Environmental Services Association of Alberta, Edmonton, AB (Canada), 29 slides, 2020

A full-scale biostimulation strategy to destroy residual petroleum hydrocarbon LNAPL is described for two sites. The goal was to enhance respiration of indigenous microbes, expedite residual source mass solubilization, and realize sustainable dissolved-phase destruction.

First Full-Scale In-Situ Propane Biosparging for Co-Metabolic Bioremediation of 1,4-Dioxane
Bell, C.H., J. Wong, K. Parsons, W. Semel, J. McDonough, and K. Gerber.
Groundwater Monitoring & Remediation [Published online 5 March 2022 before print]

In-situ propane biosparging was applied full-scale to treat 1,4-dioxane at the Vandenberg Space Force Base in California. The full-scale treatment system was installed after conducting pilot tests, stable isotope testing, and rebound testing. The biosparge system supplies air and propane at an average of 5 kg (11 lbs) propane/day to a network of 97 biosparge wells, or 52 g (0.11 lbs) propane/day/biosparge well. In addition, a bioaugmentation culture and macronutrients were delivered to the subsurface. After ~6 months of operation, 1,4-dioxane was reduced by ≤99.2%, with an average global reduction of 64.1% across a treatment area of ~30.5 by 61 m (100 by 200 ft).

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