Dr. Zareen Khan, Lecturer, Center for Environment, Institute of Science & Technology, Jawaharlal Nehru Technological University, Kukatpally, Hyderabad-7, India, Tel: +914023058729, Fax: +914023058729, Email: zareenkhan123@yahoo.co.in
Prof. Y. Anjaneyulu, Director, Institute of Science & Technology, Jawaharlal Nehru Technological University, Kukatpally, Hyderabad-7, India, Tel: +914023058729, Fax: +914023058729

Chemical pollution of the environment has become a major source of concern. Bioremediation technologies are today well established for the clean up of chemically contaminated land and many technologies are applied commercially in large scale. Composting matrices and composts are rich sources of microorganisms which can degrade pollutants to innocuous compounds such as CO₂ and water. In the present study composting of contaminated soil and sediment from Patancheru industrial area (Hyderabad, A.P, India) was performed on a laboratory bench scale pile. Fertilizer was added to increase the nutrient content and addition of commercial compost provided a rich source of microorganisms. After maintaining proper composting conditions the feasibility of composting was assessed by monitoring pH, total volatile solids, total microbial count, temperature and hazardous organic concentration. The entire composting process took five weeks resulting in degradation of hazardous organics and production of a compost with a high nutritional content which can be used as inocula for treatment of hazardous waste dumpsites.

Rapid Biological Treatment of Residual DNAPL With Slow Release Electron Donor HRC-X™

Stephen S. Koenigsberg, 1011 Calle Sombra, San Clemente, CA  92673, Tel: 949-366-8000, Fax: 949-366-8090, Email: skoenigsberg@regenesis.com
Anna Willett, Regenesis, 1011 Calle Sombra, San Clemente, CA  92673, Tel: 949-366-8000, Fax: 949-366-8090, Email: awillett@regenesis.com

The use of in situ bioremediation to stimulate the rapid dissolution, desorption, and biodegradation of residual DNAPL has been demonstrated in the laboratory and in well-documented field studies.  Biodegradation of dissolved-phase contaminants increases the partitioning and subsequent biodegradation of residual DNAPL to the aqueous phase by (1) increasing the concentration gradient and driving force for dissolution and desorption and (2) increasing the overall solubility of the DNAPL by production of hydrophilic daughter products. 

Specifically, the application of the slow release electron donor substrate, Hydrogen Release Compound-Extended Release (HRC-X™), has been successful in remediating high concentrations (>100 mg/L) of chlorinated ethenes, like PCE and TCE in residual DNAPL environments.  In situ bioremediation with HRC-X is a low-cost method for residual DNAPL removal and avoids the costly and lengthy assessment associated with defining the exact location of the dispersed residual DNAPL.

HRC-X is a highly concentrated electron donor for bioremediation and has a field longevity of at least 3 years, as verified by field measurements of lactate and its derivative organic acids.  Injection of HRC-X directly into the general residual DNAPL area of a contaminated aquifer results in the continuous release of lactic acid and fermentation of the lactic acid to hydrogen in and downgradient of the injection area.  Hydrogen from HRC-X is used as an electron donor for reductive dechlorination, which results in dissolution of residual DNAPL and desorption of sorbed contaminants. 

This presentation includes a description of HRC-X, as well as the mechanisms by which chlorinated ethene contaminants are dissolved, desorbed, and degraded.  Case histories describing successful field applications of HRC-X and total project cost will be presented.

The Efficacy Of Oxygen Release Compound (ORC®):  A Nine-Year Review

Stephen S. Koenigsberg, 1011 Calle Sombra, San Clemente, CA  92673, Tel: 949-366-8000, Fax: 949-366-8090, Email: steve@regenesis.com
Anna Willett, Regenesis, 1011 Calle Sombra, San Clemente, CA  92673, Tel: 949-366-8000, Fax: 949-366-8090, Email: anna@regenesis.com

Oxygen Release Compound (ORC®) is proprietary formulation of intercalated magnesium peroxide that releases oxygen slowly and facilitates the aerobic bioremediation of a range of environmental contaminants, including petroleum hydrocarbons, certain chlorinated hydrocarbons, ether oxygenates (e.g. methyl tert-butyl ether [MTBE]), ammonia, certain herbicides, and arsenic.  The history of ORC’s introduction and acceptance represents a model for the evolution of an innovative technology. This statement comes by virtue of the fact that, since 1994, ORC has been applied 8,900 times worldwide and has been the subject of an extensive body of literature. This technology, known as a “time release electron acceptor”, has now been clearly established as a sensible strategy for engineering accelerated bioattenuation on sites where design, capital, and management intensive options are either undesirable or contraindicated. ORC can be configured as a permeable reactive barrier, applied as a broader plume treatment, and emplaced post-excavation as part of the backfill.  This presentation will summarize results from numerous field applications of ORC.  Some guidelines for using ORC have also emerged.  It is contraindicated at sites where the BOD/COD load, seasonal or otherwise, is excessive or poorly understood, i.e., the technology is best applied to dissolved phase plumes and moderate levels of residual NAPL, once the majority of the source is removed.  ORC was first used for the remediation of BTEX and TPH groundwater contamination, and other applications have since been made for an array of other aerobically degradable compounds such as vinyl chloride, pentachlorophenol, polycyclic aromatic hydrocarbons and MTBE.  With respect to MTBE, as early as 1996, consultants using ORC noticed that MTBE concentrations decreased at a higher than expected rate. In concert with published evidence that ethers are aerobically biodegradable, additional field experiments demonstrated that oxygen can indeed enhance the remediation of MTBE; a concept that has since been verified in other quarters.  

Enhanced In-situ Bioremediation of a Complex Free-Phase Plume of No. 6 & No. 2 Fuel Oils and Motor Oils Below a Permanent Structure: Selecting the Remedy

Patrick Korths, B.A., S E A Consultants Inc., 485  Massachusetts Avenue, Cambridge, MA 02139, Tel: 617-498-4651, Email: patrick.korths@seacon.com
William Mallio, Ph.D., S E A Consultants Inc., 485 Massachusetts Avenue, Cambridge, MA 02139, Tel: 617-498-4635, Email: william.mallio@seacon.com

An evaluation of options for heavy-oil remediation was required at a major urban bus terminal.  Significant constraints were imposed on selecting a remedy because the terminal operates 24 hours a day, seven days a week, 365 days a year.  Based on operational constraints and bench-scale feasibility testing, an enhanced in-situ bioremediation program was selected as a remedy to cleanup a 200’ x 75’ complex free-phase plume of No. 6 & No. 2 fuel oils and motor oils, that partially extends under a permanent structure at the bus terminal.   A total of 25 four-inch ID access wells were installed in a 10’ x 10’ grid to allow the periodic inoculation of microbes and nutrients to the subsurface.  Soil access ports and groundwater monitoring wells were also installed to allow bi-monthly sampling to monitor and evaluate nutrient levels (i.e., nitrates, nitrites and total phosphorus) and petroleum hydrocarbon concentrations.  Remediation is currently ongoing, however initial Total Petroleum Hydrocarbons (TPH) and Extractable Hydrocarbons (EPH) analyses of soil and groundwater samples indicate a substantial reduction of petroleum hydrocarbons.  TPH and EPH concentrations decreased at certain sampling locations from above 10,000 parts per million (ppm) to less than 1,000 ppm.  The implementation of this bioremediation remedy program has provided encouraging results in the reduction of petroleum hydrocarbons, had minimal impacts on the operation of the bus terminal, and provided the Potentially Responsible Party (PRP) with a cost effective remedial approach, as compared to other possible remedial alternatives (e.g., soil excavation and removal with dewatering).  Continued monitoring will assess long-term effects and compliance with closure standards under the Massachusetts Contingency Plan (MCP).

Field Demonstration of Three Techniques for Bioremediation of Chlorinated Ethenes at Naval Station Treasure Island

Daniel P. Leigh, Shaw Environmental and Infrastructure, Inc., 4005 Port Chicago Highway, Concord, CA 94520, Tel: 925-288-2193, Fax: 925-288-0888, Email:  Daniel.leigh@shawgrp.com
Tarek Ladaa, Shaw Environmental, Inc., 312 Directors Drive, Knoxville, TN  37923, Tel:  865-670-2708, Fax: 865-690-3626
Robert J. Steffan, Ph.D., Shaw Environmental, Inc., 4100 Quakerbridge Rd.,  Lawrenceville, NJ  08648, Tel. 609-936-9300, Fax. 609-936-9221, Email:  Rob.steffan@shawgrp.com

Chlorinated ethenes, including tetrachloroethene (PCE) trichloroethene (TCE), dichloroethene (DCE) and vinyl chloride (VC), are a major source of groundwater contamination in the United States. In situ anaerobic bioremediation (ISAB) has been shown to be an effective technology for remediation of chlorinated ethenes. Various techniques have been developed to improve the ISAB process including bioaugmentation, hydrogen amendment and utilization of various substrates. Groundwater at Naval Station Treasure Island (TI) Site 24 has been affected by discharges of PCE at concentrations in excess of 20,000 µg/L. A pilot test was designed and conducted to evaluate ISAB methods to treat the high concentration source area. The pilot test evaluated three separate ISAB techniques including 1) lactate addition alone, 2) lactate and bioaugmentation with the SDC-9 culture and 3) lower concentration of lactate supplemented with hydrogen. The techniques were implemented simultaneously in three adjacent, hydrologically separate groundwater recirculation loops established in the chlorinated ethene source area. Real-time polymerase chain reaction (PCR) analysis was conducted in the field to quantify the dechlorinating organism Dehalococcoides sp (DHC) during SDC-9 injection and after biodegradation. The concurrent pilot tests successfully demonstrated the benefits of each ISAB technique. As anticipated, ISAB with only lactate was demonstrated to be an effective technology for degrading chlorinated solvents. However, bioaugmentation with the SDC-9 culture substantially increased the biodegradation rates and resulted in rapid and complete dehalogenation of chlorinated ethenes to ethene.  The distribution of the SDC-9 throughout the bioaugmentation loop was confirmed by the PCR analysis. The addition of hydrogen demonstrated a technique by which the mass of substrate (i.e., lactate) added to support dehalogenation could be substantially reduced. The successful pilot test demonstrated the value of several techniques that will be used in the full-scale remedial design.  

Aerobic In-Situ Bioremediation (ISB) of Semi-Volatile Organic Compounds (SVOC) via an Oxygen Gas Injection System

Kenneth L. Sperry, Xpert Design and Diagnostics, LLC, 1275 Glenlivet Drive, Suite 100, Allentown, PA 18106, Tel: 484-224-3031, Fax: 484-224-2999, Email: Sperry@xdd-llc.com
Omer J. Uppal, Xpert Design and Diagnostics, LLC, 22 Marin Way, Stratham, NH 03885, Tel: 603-778-1100, Fax: 603-431-7807, Email: Uppal@xdd-llc.com
Dennis Keane, , Xpert Design and Diagnostics, LLC, 22 Marin Way, Stratham, NH 03885, Tel: 603-778-1100, Fax: 603-431-7807, Email: Keane@xdd-llc.com
Matthew Nelson, , Xpert Design and Diagnostics, LLC, 22 Marin Way, Stratham, NH 03885, Tel: 603-778-1100, Fax: 603-431-7807, Email: Nelson@xdd-llc.com
Jaydeep Parikh, , Xpert Design and Diagnostics, LLC, 22 Marin Way, Stratham, NH 03885, Tel: 603-778-1100, Fax: 603-431-7807, Email: Parikh@xdd-llc.com
John L. Persico, Blasland, Bouck & Lee, Inc., 8 South River Road, Cranbury, NJ 08512, Tel: 609-860-0590, Fax: 609-860-8007, Email: jlp@bbl-inc.com
Joseph J. Tota, United Technologies Corporation, United Technologies Building, 1 Financial Plaza, MS 518, Hartford, CT 06101, Tel: 860-728-6510, Fax: 860-728-6570, Email: totajj@corphq.utc.com

Aerobic ISB is being evaluated as an alternative to an existing groundwater extraction system for treatment of aniline and nitrobenzene present as a dense non-aqueous phase liquid (DNAPL) at a site in New Jersey.  The geology at the site consists of overburden soils overlying the Passaic Formation, a sedimentary rock that consists of interbedded sandstone, siltstone, shale, and conglomerate.  Poorly sorted sands with some gravel and occasional silt and clay beds characterize the overburden.  The upper portion of the Passaic Formation is highly weathered and fractured.

The basis of design of the ISB system was a field trial conducted between March and August, 2002.  Low-flow pulsed injection of oxygen gas was performed for a period of 64 days during which approximately 4,200 pounds of oxygen were injected into the overburden and weathered bedrock via four injection wells.  Rapid dispersion of dissolved oxygen was observed in groundwater and SVOC concentrations were reduced by greater than 90% within five weeks.  First-order biodegradation rates for aniline and nitrobenzene were calculated to be less than 10 days (expressed as a half-life).

Full-scale implementation of the ISB system is being performed in a phased approach, with the first phase acting as an extended pilot test.  The Phase I ISB system consists of an array 32 oxygen injections wells in the overburden and weathered bedrock spaced 40 to 80 feet apart in an area approximate 160 feet wide by 400 feet long and began operation in December 2003.  The oxygen supply system is comprised of a 3,000 gallon liquid oxygen storage tank and evaporator and a fully automated oxygen distribution system housed in a portable trailer.  Oxygen gas is pulse injected in two-minute intervals every half-hour.  Groundwater monitoring results from the first six months of operation of the Phase I ISB system will presented. 

Anaerobic Bioaugmentation Approaches for Treating Chlorinated Solvent Contaminated Aquifers

Robert Steffan, Shaw Environmental, Inc., 4100 Quakerbridge Rd, Lawrenceville, NJ  08648, Tel. 609-936-9300, Fax. 609-936-9221, Email:  Rob.steffan@shawgrp.com
Tarek Ladaa, Shaw Environmental, Inc., 312 Directors Drive, Knoxville, TN  37923, Tel:  865-670-2708, Fax: 865-690-3626
Simon Vainberg, Shaw Environmental, Inc., 4100 Quakerbridge Rd., Lawrenceville, NJ  08648, Tel. 609-936-9300, Fax. 609-936-9221, Email:  Simon.vainberg@shawgrp.com
Daniel Leigh, Shaw Environmental and Infrastructure, Inc., 4005 Port Chicago Highway, Concord, CA 94520, Tel: 925-288-2193, Fax: 925-288-0888, Email:  Daniel.leigh@shawgrp.com

Chlorinated solvents, including tetrachloroethene (PCE) and trichloroethene (TCE), are major groundwater contaminants throughout the United States.  Extensive research and clean-up activities have demonstrated that these compounds can be biologically degraded in situ provided the correct environmental conditions exist and the proper microorganisms are present.  In many cases, biodegradation can be initiated and performed by simply adding a supplementary carbon source (i.e., electron donor) to generate reducing conditions and provide reducing equivalents for biological reductive dehalogenation.  In other cases, however, the addition of an electron donor alone does not support rapid site remediation, or biodegradation is incomplete.  This is often caused by insufficient numbers of effective chlorinated solvent degrading microorganisms.  In these cases, bioaugmentation can be used to achieve complete detoxification.  Microbial cultures for bioaugmentation can be obtained commercially (i.e., exogenous cultures), or they can be isolated from active areas of a target site (i.e., indigenous cultures) and re-applied into inactive zones.  This latter approach eliminates many of the concerns of introducing foreign cultures into resident aquifers, while allowing the use of organisms already adapted to survival in the target environment.  We will describe the enrichment, characterization, and application of Shaw’s Dechlorinating Consortium (SDC)-18 obtained from Area 18 at Lake City Army Ammunition Plant, and SDC-9 obtained from IR Site 9 at NAS North Island.  The cultures enriched from these sites all contain Dehalococcoides sp., and are capable of dechlorinating PCE, TCE, and their daughter products to ethene via halorespiration.  Data will be presented on the large-scale growth of SDC-9 for field-scale inoculation, and results of a successful field application of in-situ bioaugmentation at NAS Treasure Island.  Special emphasis will be given to the time required to enrich and grow cultures, the challenges of growing large volumes of dehalogenating cultures, and remediation costs of the bioaugmentation approach.

Results of a Successful Enhanced Reductive Dechlorination Pilot Test under the SITE Program  

Anna Willett, Regenesis, 1011 Calle Sombra, San Clemente, CA  92673, Tel: 949-366-8000, Fax: 949-366-8090, Email: awillett@regenesis.com
Stephen S. Koenigsberg, 1011 Calle Sombra, San Clemente, CA  92673, Tel: 949-366-8000, Fax: 949-366-8090, Email: skoenigsberg@regenesis.com
Robert D. Norris, Brown and Caldwell, 1697 Cole Boulevard, Golden, CO, 80401, Tel: 303-239-5421, Fax: 303-239-5454, Email: bnorris@brwncald.com
Willard Murray, 502 Washington Street, Gloucester, MA, 01930, Tel: 978-944-1778, Email:willard.murray@verizon.net

Hydrogen Release Compound (HRC®) and HRC Primer, a faster releasing version of HRC, were used in a pilot demonstration test to enhance reductive dechlorination of perchloroethene (PCE) and trichloroethene (TCE) in groundwater. A substantial amount of data, including concentrations of volatile organic compounds (VOCs), geochemical species, and organic acids were collected because the project was conducted under the United States Environmental Protection Agency (US EPA) Superfund Innovative Technology Evaluation (SITE) Program.  Enhanced reductive dechlorination was selected because of its known effectiveness in treating PCE and corresponding daughter products down to low regulatory levels. 

Data was collected for VOCs and geochemical parameters for two transects and a number of other wells over a 4-year period.  The data showed that TCE concentrations were reduced by 88 to 98 percent, and cis-dichloroethene (cis-DCE) was produced and then degraded.  Additionally, significant amounts of vinyl chloride and ethene were produced.  Geochemical parameters responded as anticipated and were consistent with biodegradation patterns.  Organic acids and elevated TOC levels were observed across the site and remained elevated through the 27 months of monitoring, as were favorable changes in the geochemistry.

In conclusion, a single application of a combination of HRC and HRC Primer was effective at initiating and maintaining reductive dechlorination of TCE through ethene for at least 27 months.  A second addition of HRC may be required to bring remediation to a close and to maintain a barrier for an extended time.  The data support observations by others that providing sufficient electron donor for a sufficient period of time can carry degradation past cis-DCE.  This presentation will give extensive data showing how enhanced biodegradation and changes in geochemistry occurred across the site and over an extended time period.  Total project cost information will also be presented.

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