DESCRIPTION OF TECHNOLOGY

Bio-Genesis Technologies has used its experience to develop an in situ technology which biodegrades contaminants in groundwater. To conduct bioremediation in situ for groundwater contamination, first, groundwater samples are collected and analysed to determine the concentration of contaminants. Next a biotreatability study is done on the groundwater to determine if bioremediation is a feasible option. If the site proves to be a good candidate for bioremediation, wells are installed for delivering oxygen, nitrogen, phosphorus, and potassium. Monitoring is conducted until the site meets clean-up levels.

Over the last seven years, Bio-Genesis Technologies  has dedicated its expertise to the innovative application of custom blended microbial cultures (GT-1000 series) and processes to naturally solve a wide variety of environmental problems.

The different formulations of microbes that Bio-Genesis Tech. develops are naturally occuring, non-pathogenic and endemic to the Earth. We use a process of selection and adaptation to identify the bacteria species with the highest propensity to degrade the targeted organic compound. To effectively degrade the various types of hazardous waste contaminants, microbiologists at Bio-GT blend several different types of microbes that have each been selectively adapted and enhanced.

Bio-Genesis Technologies can perform Biotreatability studies to determine the indegenous bacteria present and which microbes in our library are capable of utilising the contaminant as a sole carbon and energy source and to estimate the rate of degradation for each contaminant. The tests will also determine the amount of nutrients, moisture and oxygen needed to complete the remediation project.

The custom blending of microbial species are put into a synergistic mixture or blend. For example, our GT-1000 HC product blend has microbes targeted to degrade crude oil, BETEX, and deisel fuel. The GT-1000 HC product metabolises short and long chain hydrocarbons found in contaminated soil and water and converts the wastes into safe by-products of carbon dioxide and water.

BIO-GENESIS Technologies has proprietary methods for certain applications of our microbial products and waste treatment systems that we design for our customers.

Bio-Genesis Technologies provides technical consulting services that enhance our ability to provide the best Biotechnological Solutions.

TECHNOLOGY HIGHLIGHTS

Bio-Genesis Tech's treatment systems, along with our custom blended microbe solutions, can treat groundwater contaminated with petroleum hydrocarbons, PAHs Aromatics, alcohols, ketones, phenols, PCBs, solvents, carbohydrates and pesticides.

The cost savings using our bioremediation products are substantial - 50 to 70 percent over incineration and landfilling - not to mention that it's 25 to 40 percent less expensive than vapor extraction.

The Bio-GT's processes can treat unlimited amounts of water and soil per day. Other advantages include that all of our products are composed of natural biological ingredients that are harmless to animal, plant and marine life.

No safety equipment is needed when handling our products and after applying our GT-1000 microbes, the by-products of the metabolisation process are water and carbon dioxide.

The biggest advantage is since the waste is treated on site, one has no future liability associated with the hauling and disposal of the waste off site.

TECHNOLOGY LIMITATIONS

The Bio-Genesis Technologies process and microbes will not degrade inorganic or synthetic compounds. But its overall effectiveness is not affected by inorganic compounds that are present in low concentrations.

The systems used to treat various sites may require a Bio-treatability study from our company before application of our microbial cultures to determine all the parameters that must be kept during treatment to succeed.

The efficiency of eliminating the contaminants will vary with temperature, moisture, site geological and chemical characteristics. If a biotreatability analysis is performed, a treatment application outline can be given to insure optimal efficiency in degrading the contaminants to clean-up levels.

OTHER COMMENTS ON TECHNOLOGY

Bio-Genesis Technologies' systems and microbial applications have been demonstrated successfully at bench scale, pilot-scale and full-scale. Full-scale systems were used to treat soil, sludge and wastewater contaminated with petroleum hydrocarbons, aromatics and polynuclear aromatic hydrocarbons.

Our microbial products are being used by engineering companies throughout the United States for bioremediating hazardous waste sites.

Continual testing and investigation is being conducted on different chemicals and application methods to treat these chemicals using our naturally occuring microbial cultures.

Vendor Name: ECOTECHNIEK B.V. Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

________________________________________________________________________ Technology Trade Name: Biopim

DESCRIPTION OF TECHNOLOGY

BIOPIM (BIOlogical Process Integrated Method) is an in situ ground water treatment system. Groundwater is pumped up with vertical extraction wells. Some contaminants are biologically removed in a biological sandfilter (BIOPIM). This biological sandfilter is operated in downflow direction, compressed air is also introduced in the biological sandfilter in downflow direction. Microorganisms are immobilised on the sand particles. The effluent of the BIOPIM, which is enriched with oxygen, microorganisms, and nutrients is infiltrated in the soil. The BIOPIM is continuously operated.

The BIOPIM is situated on the surface of the location (see flow diagram) and is an integrated part of the recirculation of ground water through the contaminated soil. Contaminated groundwater is purified in the BIOPIM and futhermore enriched with oxygen, nutrients, and microorganisms before it is injected in the contaminated soil again. Due to the enrichment of the reinjected groundwater, biologically processes occur in the contaminated saturated soil zone.

TECHNOLOGY HIGHLIGHTS

The design of the BIOPIM is based on the load of the contaminants. The volume of the bioreactor is 0.1 to 0.5 cubic meter per cubic meter groundwater treated depending on the load of contaminants. If the concentration of the contaminant is below 2 mg/L, the volume of the bioreactor is 0.1 cubic meter per cubic meter of groundwater that has to be treated. Contaminants which can be treated are organic compounds that are biologically (aerobic) degradable such as BTEX, TPH, phenol, and monochlorobenzene. Contaminants that are delivered to the bioreactor a degraded in the bioreactor. However, much of the biological degradation takes place in situ as water enriched with oxygen, nutrients, and microorganisms are delivered to the subsurface. Compared to other systems the bioreactor is very compact. The remediation costs lie between 0.1 and 2.0 Dutch Guilders per cubic meter groundwater depending on the flow and the load of contaminants.

TECHNOLOGY LIMITATIONS

The maximum capacity of one BIOPIM is 30 cubic meters of groundwater per hour. At higher flowrates several BIOPIMs have to be operated in parallel sequence. The influent concentrations can be as high as 100 mg/l for BTEX and TPH. At iron concentrations higher than 25 mg/L a pre-iron removal step has to be installed.

Metals and (in) organic contaminants which are not degradable by aerobic biodegradation such as perchloroethylene are not removed.

OTHER COMMENTS ON TECHNOLOGY

The first full-scale BIOPIM began operation in 1992 and is still successfully in operation. By 1994 five full-scale BIOPIM installations are successfully in operation at in situ bioremediation projects in the Netherlands.

Vendor Name: ABB ENVIRONMENTAL SERVICES, INC. Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

ABB Environmental Services, has designed and implemented several full-scale in situ groundwater biological treatment systems.

Contaminated water and soil below the water table are treated by stimulating naturally occurring bacteria to biodegrade the contaminants in place. Biological activity is enhanced by the delivery of ABB-ES specially formulated nutrients, and dissolved oxygen through the injection of hydrogen peroxide. Treatment designs include the recirculation of groundwater or the creation of biological barriers for plume interception.

This technology has been applied to aquifers contaminated with BTEX and petroleum products, coal tar wastes, and industrial feed stock chemicals.

The two-zone plume interception treatment technology is designed for in situ bioremediation of chlorinated solvents in groundwater and saturated soils. The technology will also treat nonchlorinated volatile and semivolatile chemicals. Chlorinated chemicals such as tetrachloroethylene at high concentrations (100mg/L) can be treated. The technology is designed to operate by establishing two subsurface zones through which a contaminated plume flows and is treated. The first zone is anaerobic and provides conditions suitable for dechlorination of highly chlorinated contaminants. The second zone is aerobic and provides conditions suitable for biological oxidation to the partially dechlorinated products from the first zone. The second zone requires that methane gas be added at a concentration of 1.0 percent in air. The two subsurface zones may be constructed through the use of trenches or parallel rows of wells positioned perpendicular to the direction of groundwater flow. If suitable indigenous bacteria are not present then bioaugmentation may be required. Bioaugmentation is a process in which special dechlorinating strains or methanogenic bacteria are inoculated into the anaerobic zone. Similarly, methanotrophic inoculum can be used for the aerobic zone. Specific nutrients are added to each zone. The anaerobic zone receives glucose or methanol.

TECHNOLOGY HIGHLIGHTS

ABB Environmetal Services Inc.'s in situ groundwater bioremediation process can treat BTEX, PAHs, or any contaminant that can be readily degraded by aerobic bacteria. The removal effectiveness can approach 100 percent.

The conventional treatment approach for aquifers contaminated with these compounds is "pump and treat" with removal by activated carbon adsorption. Biological treatment can be more cost-effective than this approach since the contaminant is destroyed on site. Costs associated with removal, transport, recovery, or incineration are avoided.

The two zone plume interception treatment technology is designed to address chlorinated chemicals that have high water solubility such as tetrachloroethylene (PCE) and trichloroethylene (TCE), etc. Other chemicals treatable by this method include chloroform, carbon tetrachloride, and methylene chloride.

TECHNOLOGY LIMITATIONS

In situ groundwater bioremediation by conventional aerobic methods cannot treat metals or chlorinated aliphatic contaminants (i.e. TCE, PCE). The addition of oxygen to an aquifer can cause clogging due to precipition of iron oxides, etc.

The two zone plume interception treatment technology has been designed for the treatment of chlorinated chemicals as primary chemicals of concern. Other chemicals will be treatable under the sequential anaerobic/aerobic conditions created by this technology. The two zone plume interception treatment technology has not been tested under field conditions.

OTHER COMMENTS ON TECHNOLOGY

ABB-ES has developed two types of in situ groundwater treatment systems. The first has been operated at full-scale and is designed to treat readily biodegradable chemicals such as benzene and toluene under aerobic conditions. The second in situ groundwater system is our two zone plume interception technology designed to treat chlorinated chemicals.

ABB Environmental Services has applied this technology to several gasoline stations, a coal tar waste site, and a chemical manufacturer. Typically, a laboratory study is required to assess the treatability of a contaminated site. This service is also provided by ABB-ES.

EMERGING TECHNOLOGY FIELD DEMONSTRATION

The process to be used in an upcoming field demonstration is the two-zone plume interception and treatment technology. This technology is designed to operate by establishing two subsurface zones through which a contaminant plume flows and is treated. The first zone is anaerobic and provides conditions suitable for biological dechlorination of highly chlorinated contaminants such as PCE. The second zone is aerobic and provides conditions suitable for biological oxidation of the partially dechlorinated products from the first zone as well as other contaminants. ABB-ES's research (bench scale testing under the EPA Emerging Technology Program) has demonstrated that sequential anaerobic-aerobic biodegredation of PCE is feasible if proper conditions can be established. EPA's willingness to fund a field demonstration indicates their concurrence with this conclusion.

Vendor Name: ENSR CONSULTING AND ENGINEERING Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

ENSR has designed and implemented a full-scale system combining several remediation technologies to treat soil and groundwater contaminated with chlorinated solvents. The system combines bioremediation, steam injection, soil vapor extraction, groundwater extraction, and air-stripping. This system has been effective in removing chlorinated solvents such as trichloroethane (TCA), and trichloroethene (TCE), present as dense nonaqueous phase liquids (DNAPLS). For this particular application DNAPLs are present at the site in unconsolidated glacial clays with measured hydraulic permeabilities ranging from 10E-4 to 10E-5 cm/sec.

The remediation approach for this technology combines the use of steam injection for the removal of dense nonaqueous phase liquids (DNAPL), coupled with the application of nutrients to groundwater to promote biotransformation of TCE and 1,1,1-TCA to compounds which are more easily removed from the subsurface.

A network of groundwater injection wells is used to deliver steam to mobilise the DNAPL in the subsurface and maintain anaerobic conditions. The steam is applied in the DNAPL phase, and not in the aqueous phase. Injection wells are also used to deliver growth substrates and nutrients into the aqueous phase to promote the growth of indigenously occuring anaerobic bacteria. Anaerobic bacteria, specifically methanogenic bacteria, biotransform TCE and TCA to dichlorinated and monochlorinated alkenes and alkanes which are more easily removed from the subsurface in the aqueous phase. Although the kinetics associated with methanogenic bacteria are slow, the transformation is intended to only convert TCE and TCA to di-or mono-chlorinated compounds, making the remediation time faster.

DNAPLs which are volatilised by close contact with injected steam are removed in the vapor phase by a network of vapor extraction wells. The vapor wells are connected to a vapor extraction unit which was custom built and designed for ENSR to be resistent to chemical corrosion. Air emissions from the vapor extraction unit are monitored using a total hydrocarbon analyzer.

DNAPLs in the liquid phase are removed by a network of groundwater extraction wells. Extracted groundwater is treated in an air-stripper to remove chlorinated solvents.

TECHNOLOGY HIGHLIGHTS

ENSR's in situ groundwater remediation process, based on a systems approach, its effective in biotransforming and removing high concentrations of chlorinated solvents, even if present as DNAPLs. The biotransformation is carried out under anaerobic conditions and therefore delivery of oxygen to subsurface microrganisms is not required. This in situ application is well suited for remediation of areas located beneath building foundations.

The conventional treatment approach for aquifers contaminated with these compounds is removal by groundwater extraction combined with aboveground treatment. ENSR's approach is to biotransform TCE and TCA under anaerobic conditions, producing dichlorinated and monochlorinated compounds. These compounds have different chemical characteristics than their parent compounds (such as move favorable aqueous solubilities, vapor pressures, and octanol-water and octanol-carbon partition coefficients), and hence are more easily removed from the subsurface. ENSR has estimated that approximately 30 groundwater pore volume flushes are required to remove 90% of the TCE from an aquifer consisting of glacial clays. Comparable removal of the degradation compounds of trans- and cis-1,2-dichloroethene only requires 4 to 6 pore volume flushes, respectively. Anaerobic biotransformation produces degradation compounds which require less volumes of groundwater to be removed, shortens the remediation timeframe, and therefore, reduces the cost of remediation.

An innovative feature of this technology is the simultaneous use of steam injection and biostimulation. Biostimulation of anaerobic bacteria, specifically methanogenic bacteria, is done by addition of growth substrates (potassium acetate and sodium formate) and nutrients to the subsurface. The conversion of TCE and TCA into their degradation products is accomplished by co-metabolism process, where these chlorinated compounds are not utilised as a primary carbon source. Additions of growth substrates, such as potassium acetate and sodium formate may form organic acids. However, the acidity induced by these compounds can be neutralised by the buffering capacity of the groundwater. No pH decrease was observed in the past.

TECHNOLOGY LIMITATIONS

This type of in situ remediation process is limited to the treatment of chlorinated solvents. Anaerobic bioremediation of most other organic compounds is less effective than aerobic biodegradation. Additionally, this technology does not treat metals.

Implementation of this technology requires pilot-scale testing to aid in design of a full-scale system. The presence of iron in the treatment zone may result in clogging of groundwater extraction wells and air stripper tower packing material. However, more prevalent problem is scaling occurred due to excessive Ca+2 and Mn+2 ions concentrations.

Injection of substrate and nutrients into groundwater will likely require a permit in most states. Care must be taken not to mobilise DNAPLs when applying this technology.

OTHER COMMENTS ON TECHNOLOGY

ENSR has been operating a full scale remediation system based on biotransformation combined with steam injection for approximately four years. A design for the remediation of a second site impacted by chlorinated solvents present as DNAPLs using a similar approach was completed in mid-1994. System installation and start-up is scheduled for early 1995. Both sites where this technology is being applied are being remediated under privately funded voluntary cleanups. Cleanup objectives for these sites were negotiated with the appropriate state agency.

Steam injection combined with biotransformation is likely to be an effective remedial technology for many sites impacted by releases of chlorinated solvents.

ENSR has also designed, installed, and operated a number of more traditional in situ groundwater biotreatment systems for the remediation of BTEX contaminated aquifers.

________________________________________________________________________ Technology Trade Name: Petroclean Bioremediation System

DESCRIPTION OF TECHNOLOGY

ESE Environmental, Inc.(formerly ESE Biosciences, Inc.), has developed the patented PetroClean Bioremediation System to treat organic contaminants found in soils and groundwater in situ. The technology is based on recovering contaminated groundwater; treating the ground water in an aboveground fixed-film bioreactor with a combination of acclimated indigenous microbes, nutrients, and oxygen; and then reintroducing the groundwater to the subsurface to flush soils and create a favorable environment for growth of contaminant-degrading microbes in soils. The approach is designed to recover and reintroduce groundwater to create a closed-loop in situ remediation system that treats soils and groundwater simultaneously.

(This technology also is listed under Bioremediation - In Situ Soil)

TECHNOLOGY HIGHLIGHTS

The PetroClean Bioremediation System treats, in situ, biodegradable contaminants (for example, gasoline, diesel fuel, aviation fuel, solvents, PNAs, VOCs, and other organic compounds) in soils and ground water. The advantages of biological treatment over traditional remedial technologies are: first, biological treatment destroys contaminants on site, thereby reducing the liability that can be incurred from the transport and disposal at off-site facilities; and second, the by-products of biological treatment are harmless (carbon dioxide, water, and biomass) and do not require further treatment. Economically, in situ biotreatment does not involve major excavation, transportation, or disposal and therefore is often one-third to one-half the cost of traditional remedial technologies. Unlike pump-and-treat technologies, in situ bioremediation treats both contaminated groundwater and soils, thereby reducing treatment time, and subsequently reducing remedial costs. Finally, because in situ bioremediation involves subsurface treatment, there is a minimal disturbance to aboveground site operation and construction activities.

The advantage of ESE's technology is that it treats both groundwater and soils in situ simultaneously. A separate system is not required to treat soils first and then ground water.

TECHNOLOGY LIMITATIONS

Removal rates are based on solubility of contamination and the ability of indigenous microbes to degrade contamination. Installation of infiltration galleries or recirculation wells is required. Effectiveness of recharge may depend on subsurface permeabilities and interactions. Permitting is often required for the recirculation process. Microbes may be sensitive to toxins in soil and groundwater. Nutrients may be agency regulated. The process may require emissions control and/or a non-discharge permit.

OTHER COMMENTS ON TECHNOLOGY

Treatment for petroleum hydrocarbons has been demonstrated in bench- pilot-, and full-scale application. Treatability research and development is currently on going for more recalcitrant compounds.

A biofeasibility analysis (BFA) is recommended to determine site-specific suitability for in situ bioremediation prior to full- scale implementation. ESE Environmental can evaluate toxicity, degradation kinetics, and model site-specific conditions during a BFA to determine if in situ bioremediation will be an effective full-scale remediation technology. The BFA examines parameters that may affect the technology limitations (see technology limitations section).

Vendor Name: KEMRON ENVIRONMENTAL SERVICES, INC. Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

KEMRON Environmental Services has developed and successfully applied an innovative in situ bioremediation technology primarily for soils but also applicable for groundwater remediation.

The key to success of the system depends on a carefully engineered, site specific, groundwater recirculation system designed to deliver nutrients and oxygen to the in situ, naturally occurring microbial community. If a natural community has not been established, microbial cells can be added with this system.

A system of infiltration and recovery galleries is installed and connected to a bioreactor and an aeration system. The system is installed as a stack of vertical trenches alternating between infiltration and recovery trenches. Natural groundwater is recirculated in a closed-loop system, starting from the infiltration galleries, through the contaminated soils, into the recovery galleries, and then through the aerator and bioreactor. The bioreactor is used to add nutrients and other chemicals as needed for the remediation process. The natural microbial community in the contaminated soils is thus stimulated to degrade the contaminants.

The system is versatile and can be designed to address a number of different contaminants and soil types. By controlling the water input, the water table can be raised in order to treat unsaturated soils or maintained in order to treat groundwater. The above ground portion of the system is small and can be installed in small existing spaces. It is designed to run continuously with little or no supervision and maintenance is minimal. The operating costs of the system are low. (This technology is also under bioremediation in situ soil).

TECHNOLOGY HIGHLIGHTS

This in situ bioremediation system can treat soils and groundwater in place with minimal disruption to ongoing activities. The treatment is entirely onsite, thus eliminating treatment off-site or disposal and consequently future liabilities. The operating costs are low and operation and maintenance activities are simple and minimal.

The system is capable of addressing contamination from petroleum products, solvents, nonhalogenated volatiles and semivolatiles, BTEX, polynuclear aromatics, and organic acids (lower chain fatty acids such as acetic acids). Full-scale application of the system resulted in the reduction of soil petroleum hydrocarbons by over 98%.

TECHNOLOGY LIMITATIONS

This system is not applicable for contaminants that are not readily biodegradable, such as chlorinated solvents, pesticides, and herbicides, PCBs, metals, and certain inorganics. The cleanup times can be long, on the order of several months, depending on the type of contaminant and initial and target concentrations.

OTHER COMMENTS ON TECHNOLOGY

KEMRON's in situ bioremediation technology has been successfully demonstrated in a full-scale application. This full-scale application was used to treat petroleum (diesel and #5 fuel oil) contaminated soil at a working industrial site. Disruption to the industrial activities was minimal. The system was reviewed and approved by the Virginia Water Control Board.

Vendor Name: REMEDIATION TECHNOLOGIES, INC. Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

In situ bioremediation addresses biodegradable organic contaminants within the saturated zone of a contaminated aquifer. The technology is a continous, in situ process treating contaminated groundwater within the saturated zone. Primary contaminants include nonchlorinated solvents, BTEX, and polyaromatic hydrocarbons. The process involves transporating nutrients (ammonia and orthophosphate) and an oxygen source through the contaminated zone to enhance biodegradation. The process requires injection wells (or trenches), recovery wells (or trenches), nutrient storage and delivery systems, monitoring wells and a surface water treatment process to remove dissolved contaminants prior to reinjection. Hydrogen peroxide or air sparging can be used to increase the availability of dissolved oxygen, depending upon site conditions.

The technology is continuous, in situ process treating contaminated groundwater within the saturated zone. Primary contaminants include nonchlorinated solvents, BTEX, and polyaromatic hydrocarbons.

TECHNOLOGY HIGHLIGHTS

This technology provides dramatic enhancement to aquifer remediation when compared to a traditional pump-and-treat process, especially BTEX and semivolatile contamination resultings from petroleum products, coal tars, and other nonchlorinated materials.

The technology is more aggressive on the compounds that are more absorbent to soils, resulting in faster remediation, and in general higher cost-effectiveness.

TECHNOLOGY LIMITATIONS

Contaminants of interest must be biodegradable. Soil permeability should be 10E-4 cm/sec or greater. Site should allow for good hydrogeologic control. OTHER COMMENTS ON TECHNOLOGY

The process has been developed for gasoline, diesel, and heating oils. RETEC is now actively developing its application at wood treating sites, petrochemical facilities, former manufactured gas plants, and superfund sites exhibiting mixtures of very diverse contaminants.

Vendor Name: SBP TECHNOLOGIES, INC. Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

SBP Technologies, Inc. (SBP) has compiled a unique collection of patented microorganisms for use in bioremediation applications. These microorganisms include strains of bacteria, mycobacteria, and fungi that utilise high-molecular-weight polycyclic aromatic hydrocarbons (HMW PAHs), chlorinated aromatics (such as PCP), and/or pesticides as sole sources of carbon and energy for growth (U.S. Patent No. 5,132,224). Further, in association with the University of West Florida and the U.S. EPA at Gulf Breeze, Florida, a bacterium capable of constitutive biodegradation of TCE and other chlorinated aliphatics and aromatics (requires no inducer or cosubstrate) has been isolated, characterised (Dr. Malcolm Shields, Patents Pending), and field tested at the pilot scale.

Innovative means of implementing these technologies in the field are being developed in association with IEG Technologies, Inc. The integrated use of these microorganisms together with in situ bioreactor technologies promise to yield an effective and cost-efficient remedial solution for groundwater contaminated by a great number of organic compounds.

The in situ bioreactor is an encapsulated cell designed to be inserted into a well. The bioreactor can be inserted to treat the vadose zone or groundwater. When treating the vadose zone a blower or vacuum may be applied to volatilise contaminants and flush them into the bioreactor.

(This technology also is listed under Bioremediation - In Situ Soil.)_

TECHNOLOGY HIGHLIGHTS

Specially selected microorganisms have been patented for the treatment of water containing organic wood preservatives, namely creosote and PCP, and chlorinated solvents, especially TCE. Application strategies using in situ bioreactors and encapsulated cells are designed on a site-specific basis with the implementation design being determined primarily by the objective of the remedial action (clean-up goals), the contaminant, and the nature of the contaminated matrix. In situ technologies use physical channeling methods and patented well designs (IEG, Inc.). As such, these systems are noninvasive and yield no water/waste requiring subsequent treatment.

In each case, the treatment niche is represented by large sites with few remedial alternatives. Due to the relatively passive nature of the technologies presented, they often offer cost-efficient, effective solutions.

TECHNOLOGY LIMITATIONS

Time constraints often limit in situ applications. All conventional limitations to biological preprocesses apply (for example, high metal concentrations, temperature, pH, nutrient status, oxygen potential, bioavailability, and so forth). Physical/hydrogeological constraints are also critical.

OTHER COMMENTS ON TECHNOLOGY

The bioremediation technologies have been developed in conjunction with the U.S. EPA Environmental Research Laboratory of Gulf Breeze, Florida (GBERL), the University of West Florida (Dr. Malcolm Shields), and IEG Technologies, Inc. SBP's role in marketing and commercialisation of these technologies is supported internationally by other collaborators that enhance these technologies by coupling innovative application strategies with the most advanced microbiological capabilities.

Vendor Name: OHM REMEDIATION SERVICES CORPORATION Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

In situ bioremediation of groundwater involves enhancing microbial biodegradation of contaminants in the aquifer. The groundwater is continuously or semi-continuously recirculated through the aquifer and is usually amended with nutrients and a suitable electron acceptor prior to reinjection.

Oxygen is the most common electron acceptor used. It can be dissolved in the aquifer water and delivered to the aquifer in the form of air, pure oxygen, or hydrogen peroxide. Microbubbles can also be used as a means of oxyen delivery.

The system used is site specific but typically involves injection/ recovery wells or trenches to recirculate groundwater after amendements have been mixed in. Bioremediation can be used alone or as a means of polishing groundwater in conjunction with other methods.

TECHNOLOGY HIGHLIGHTS

Many types of contaminants can be treated economically using this technology. Petroleum hydrocarbons, benzene-toluene- ethylbenzene-xylene (BTEX), nonchlorinated solvents, and in some cases chlorinated solvents can be completely biodegraded. In many cases bioremediation is used as a polishing process after other physical means, such as air stripping for volatile compounds or an oil-water separator for petroleum hydrocarbons. When equipment has previously been installed for physical treatment, bioremediation can be implemented at low cost with the addition of nutrient holding and mixing tanks. When remote monitoring equipment is used, labor costs are low as well.

TECHNOLOGY LIMITATIONS

Lack of available oxygen may limit the rate of biodegradation to the extent that oxygen may need to be delivered to the aquifer. Microbubbles may be used to deliver oxygen to the aquifer. Contaminants that are tightly bound to the soil or that are present in the form of nonaqueous-phase liquids (NAPL) may limit the bioavailability of contaminants and decrease the rate of biodegradation.

Some contaminants may be toxic to the microbial population. Likewise, highly chlorinated compounds may not be amenable to biodegradation. In such cases, a treatability study can be performed prior to field implementation to determine if the the contaminant concentration is toxic to the indigenous bacteria or whether an adapted bacterial population can biodegrade the contaminants.

Vendor Name: ELECTROKINETICS, INC. Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

The electrokinetic bioremediation (or bioelectrokinetic remediation) technology for continuous treatment of groundwater or soil in situ,, utilises either electroosmosis or electrochemical migration (ion migration) to initiate or enhance in situ bioremediation. The first case of electroosmosis represents the situation where a direct current can produce an accelerated flow of groundwater in the soil strata. Electroosmosis flow develops more easily in sands, sandy silts, or sandy clays. Biological growth factors including microbial populations, surfactants, inorganic and organic nutrients can be moved and often directed into the soil and groundwaters matrices. Electroosmosis in this case can be used to accelerate the natural groundwater movement and increase the efficiency of the biodegradation process by the addition of the biological agents into the coarse soils. The flow, however, in coarse grain soils will tend to follow natural fissures or high permeability lenses and not be uniform throughout the bed. Thus the possibility exists that high concentrations of organic pollutants may not be remediated.

The second case which represents the situation in stiff silty clays and mixed clays is different. Electroosmosis has limited or no effect on groundwater movement. Thus electrochemical or ion migration is now the dominant process. The electrical field will move uniformly through the soil and electrical ions will readily pass through the small clay pores. Natural biological populations always exist around organic pollutant spills in soils. Complex organic compounds, however, are not prime energy sources for microbial populations and biodegradation will not start until sufficient food, nutrients, and electron acceptors are available to initiate exponential growth while reducing the organic pollutant concentration. The small bacteria found in clay soils are typically the rod-shaped Pseudomonas, and if no source of food is available the bacteria remain in the resting stage until activated. The electrical field in this case will be used to spread charged soluble inorganic and some simple organic nutrients uniformly though the site and direct these nutrients to the spatial location where the food source (hydrocarbon pollutant) is located. Bench-scale work is now in progress on this second alternative. This alternative is applicable to soils and groundwater.

The pH of the soils can be readily adjusted by buffering agents to avoid toxic shock to the microbial populations.

This technology is also listed under bioremediation - in situ soil.

The electrochemistry of hydrolysis of water and acid/base reactions is described in our technology listed under "Electrical Separation."

TECHNOLOGY HIGHLIGHTS

The contaminants treated would include halogenated hydrocarbons such as TCE and nonhalogenated organic pollutants such as BTEX and polynuclear aromatics. The process is expected to work on spills of petroleum hydrocarbons such as gasoline, diesel fuel, kerosene, and lubricating oils. The technology is predicted to work in unique applications such as directing nutrients into areas where UST's are leaking or spills have occurred.

An important feature of this technology is that there is normally no requirement to add microorganisms. The technology is designed to activate the dormant populations by use of selected nutrients which will promote growth, reproduction, and metabolism of the microorganisms to breakdown the organic pollutant. The bioelectrokinetic technology (ELECTRO-KLEAN) will direct the nutrients to the organic pollutant. Major savings are obtained because outside microbial populations are not required and nutrients can be uniformly dispersed over the contaminated volume of soil and even directed at a specific location, thus reducing nutrient cost. This process should be extremely valuable as it solves the problems associated with trying to transport microorganisms through fine-grained soils.

Soluble organic pollutants in plumes can be degraded by injection of acclimated and adapted microbial populations into the plumes at strategic points. Biodegradation is a slow process, but if fast options such as excavation and disposal are too expensive, or not applicable, then this process will be highly competitive.

Simple nutrients such as sodium nitrate will typically be used, and costs are predicted to be very low, as nutrients can be directed to selective subsurface locations where the hydrocarbons are located.

TECHNOLOGY LIMITATIONS

Concentration of hydrocarbons may be too high for either indigenous microbial population or superimposed acclimated populations to start biodegradation. (The concentration of the organic pollutant is above the toxic threshold limit of the microbial population).

Unforeseen problems may prevent uniform and/or directed distribution of nutrients into the microbial population/hydrocarbon matrices thus preventing the microbial populations from performing effective bioremediation.

The bioremediation of mixed organic pollutants may produce byproducts which are toxic to the microorganisms and stop the biodegradation process. This would be most likely to occur in a stationary environment where the toxic byproducts would remain in proximity to the microbial populations.

OTHER COMMENTS ON TECHNOLOGY

Electrokinetics, Inc. has developed a strong research and development plan. The response of soil microorganisms to various levels of direct current is being studied. One of our first pilot tests for the electrokinetic bioremediation program will be to compare removal of jet fuel from contaminated sites with other conventional remediation processes.

An important function of the bio-electrokinetic process is the use of dissolved oxygen generated at one the anodes (water electroysis) which provides an aerobic environment for the injected or indigenous microbial populations. Additionally, it is believed that the DC electric current used to move electron acceptors (oxygen, nitrates, carbonates) also increases the energy level of the microbial populations and initiates the bioremediation process.

Vendor Name: GEO-MICROBIAL TECHNOLOGIES, INC. Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

The presence of hydrogen sulphide (H2S) in wastes and waters is a known hazard and will cause product deterioration and corrosion in all types of industrial processes and situations. The generation of H2S by sulfate reducing bacteria is of particular concern to the oil, chemical, and water industries since such organisms generate H2S from sulfate and cause corrosion. The prevention and removal of H2S will reduce industry costs and environmental problems. An in situ biotreatment process has been developed which uses microorganisms to remove the H2S. This process operates in the absence of air with no production of acid. This process introduces and establishes specific microorganisms in the system which consume the available H2S removing it from the system while at the same time preventing its formation by reducing and eliminating the nutrients required for the sulfate reducing bacteria. This bioremediation process will prevent the formation of H2S and will remove the H2S already present in the waste.

- Process involves injection of a fluid which contains microorganisms, nitrates, and other nutrients into an environment high in H2S. These microorganisms will out-compete the sulfate reducing bacteria to remove and prevent the generation of H2S

- Process is in situ.

(This techology is also listed under Bioremediation - In Situ Soil)

TECHNOLOGY HIGHLIGHTS

This hydrogen sulphide (H2S) prevention and removal process can be conducted under the same in situ conditions as currently operated systems in which the H2S is generated. Thus anaerobic conditions are maintained and no capital costs would be added. Specific biotreating cultures are introduced by conventional injection technologies. These factors reduce the cost for this bioremediation treatment. The H2S is completely removed from the system in situ together with the elimination of the sulfate reducing bacteria which cause its generation. The process is simple to operate and requires only minimum control. The employed organisms are nonhazardous and the products generated are non-toxic so the system is environmentally acceptable.

- Technology can be applied to any situation where H2S is produced (landfills, leaking USTs, contaminant plumes etc...)

- Marketable features include low cost, low maintenance, environmentally safety, and simplicity.

TECHNOLOGY LIMITATIONS

Waste applicability: This system is designed to operate within and with minimum alteration to the hydrogen sulphide (H2S) contaminated area or environment.

- Requires anaerobic conditions, nutrients, and a transportation media (water/brine).

- Organism growth is not limited by the presence of hydrocarbons, other organic compounds, or metals.

Compound specific (H2S).

OTHER COMMENTS ON TECHNOLOGY

Test Results: Laboratory tests in core systems using field waters and conditions have demonstrated the effectiveness of the technology. These model core studies spanning a period of years have identified the conditions and treatment levels necessary for successful remedial treatments. The system has been demonstrated at conditions up to 65 degrees Celsius and in the presence of salt and oil. The process has been developed to utilise an enhancement of the indigenous microflora or could involve the supplementation of such populations with selective cultures adapted and tailored to the specific site and environment. Demonstrations of the complete cessation of H2S generation and the removal of the H2S already present offer a dual function remediation process.

Vendor Name: EODT SERVICES, INC. Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

EODT Services has several in situ treatment methods. One of the effective methods is soil flushing and bioremediation in situ of ground water, which involves the elutriation of organic and/or inorganic contaminants from soil for removal and treatment. First the site is flooded with appropriate washing solution/biodispersant, and then elutriate is collected in a series of shallow wellpoints or subsurface drains. The elutriate is then treated above ground within a liquid phase bioreactor and then released into the ground water table. Depending on the subsurface soil condition, bacteria is also recirculated into the subsurface soil to enhance the biodegradation.

TECHNOLOGY HIGHLIGHTS

Instead of only in situ treatment, this technology is also coupled with onsite (pump and treat) treatment to enhance the rate of contaminant degradation.

The key component of this process is the biodispersant which basically desorbes the contaminant chemical and also server as a high energy nutrient for the microorganisms.

TECHNOLOGY LIMITATIONS

1. Biodispersant desorbs many organic chemicals from soil. But its effectiveness has never been tested on many other chemical contaminants attached to the soil matrix. So some bench-scale test on a particular soil contaminant is necessary before any pilot-scale study.

2. Maintaining (supplying) proper concentration of inorganic nutrients. Excess nutrients create an inhibitory condition for the bacteria to grow. Nutrients supply must be monitored with bacteria growth.

3. In situ aeration/methanation to subsurface soil is important in specific cases. A sandy soil is more preferable than clays. Aeration in tight formations becomes difficult, sometimes, impossible due to excessive clay layers.

OTHER COMMENTS ON TECHNOLOGY

Vendor Name: ECOLOGY TECHNOLOGIES INTERNATIONAL, INC. Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

FyreZyme is a multifactoral liquid (aqueous) agent, combining a rich source of bacterial growth-enhancing agents, extracellular enzymes, and bioemulsifiers. The bacterial growth enhancers induce a logarithmic growth phase in native soil bacteria, while the extracellular enzymes initiate the oxidative process in petroleum contaminant degradation. The enhanced bacterial population adapts to the presence of the partially-oxidised contaminant, utilising it as a source for further preferential growth of petroleum-degrading organisms, both aerobic and anaerobic. Biodegradable bioemulsifiers/surfactants help move the aqueous solution through the soil, mobilising petroleum and cleaning blocked soil pore spaces.

For in situ treatment, a "front" of FyreZyme-containing aerated water is moved through the ground water by a combination of infiltration galleries or injection wells upgradient and extraction wells downgradient. Ground water may be recycled through the bioremediation bed for both maintaining moisture levels for metabolic activity and for cleansing of ground water. If permitting requires that ground water extracted be cleansed prior to reinjection or discharge, suitably sized holding tanks with aeration lines to maintain aerobic conditions are utilised as bioremediation reactors. As the ground water is extracted, there is usually sufficient FyreZyme residual that little or no additional enhancement is needed.

FyreZyme is non-toxic to the standard EPA-recommended test of marine vertebrate and invertebrate forms, and non-toxic by ingestion or chronic inhalation in Sprague-Dawley rats, guinea pigs, and produces negative sensitivity in skin and conjunctival application to New Zealand white rabbits. It is authorised for use by On-Scene Commander on all navigable waterways in US by EPA, with standard disclaimer of endorsement or approval by that agency. (This technology is also listed under Bioremediation - in situ soil. For off-gas treatment, see the description for off-gas treatment.)

TECHNOLOGY HIGHLIGHTS

FyreZyme is a concentrated aqueous solution, which is diluted to 4,5, and 6 percent for use as a bioremediation enhancing agent. FyreZyme is stable, with a shelf life of 5 years under "normal" environmental conditions. FyreZyme is effective in accelerating bioremediation of a wide range of organic contaminants in an environmentally friendly, scientifically sound, and cost-effective manner. FyreZyme may be used as a stand-alone technology or incorporated into other technologies, such as bioventing, soil venting, sparging, slurry phase treatment, sediment treatment, pump-&-treat, etc..

Among the advantages to FyreZyme are its ease of use, permanent solution to contamination, and affordability. When used to eliminate volatile organic compounds (VOC), the cost is less than 10 percent that of granular activated carbon (GAC). When used as primary bioremediation agent, the cost ranges from $6-8 per cubic yard, exclusive of engineering costs. If added to the ongoing technologies mentioned above, the cost is negligible compared with expenditures on typical phase-transfer technologies.

TECHNOLOGY LIMITATIONS

The main limitations are those that limit bacterial growth, such as temperature extremes, pH below 3 or above 10, and contaminants harmful to bacteria in high concentrations. If temperature is above 100 degrees Fahrenheit, the shelf life of FyreZyme may be shortened to 2 years from 5 years. Enzyme poisons must be flooded with FyreZyme before bioremediation will ensue.

In soils with low permeability value, movement through soil is noticeably faster than that of ground water due to the presence of biodegradable emulsifiers/surfactants.

OTHER COMMENTS ON TECHNOLOGY

An in situ field program is in progress with Mobil Oil, using a combination of upgradient vertical and horizontal injection wells and a downgradient extraction well.

An in situ program is currently in progress in Waco, Texas, at a tire manufacturing plant (name withheld at client's request). A second project is underway at a California-Nevada border location, and a third one is undergoing engineering study beneath an intersection in a major metropolitan area.

Vendor Name: GAIA RESOURCE, INC. Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

GAIA Resource, Inc. has developed GAIA-NET a cost-effective application technology to clean up hazardous waste sites. The GAIANET technology is applicable but not limited to Bioremediation - In Situ Ground Water. Specifically GAIA-NET is designed to remediate remote, inaccessible subterraneous groundwater in aquifers and porous media.

After hydrogeological, chemical and biological analysis of the subsurface is complete and parameters are known, a network of plastic tubing is injected in the contaminated plume and microbes are injected to destroy the contaminants.

An impermeable vertical barrier or lining is installed with a vibratory hammer and insertion plate to maintain hydrogeologic control. The technology is capable of reaching depths of up to 100 feet.

GAIA-NET can be used for the remediation of military sites contaminated with hazardous, toxic, and radioactive materials.

TECHNOLOGY HIGHLIGHTS

TECHNOLOGY LIMITATIONS

The success of GAIA-NET requires groundwater modelling, and enterprise which requires expertise in several disciplines. Key nuclear, chemical and biological processes are relatively well understood. Mathematical models are used to represent processes that involve biotransformation, subsurface reactions, or mineral dissolutions/precipitation reactions. However, fundamental gaps in knowledge still exist in describing the complex interactions that may occur among constituents. For instance, knowledge of co-solvent effects in surface reactions, interactions between several biological substrates and mixtures of inorganic substrates in real aquifers and oxidation-reduction reactions is limited.

Although the biological reaction process is not sophisticated, it seems to be adequate for modelling on large spatial scales, and has been used successfully in practice to clean up petroleum hydrocarbons.

OTHER COMMENTS ON TECHNOLOGY

The GAIA-NET technology has proven successful in petroleum and natural gas field production.

Two full-scale systems are designed and planned for implementation subject to site specific modification.

GAIA Resources, Inc has knowledge of and experience in the field of emergency cleanup and disposal operations, with critical knowledge of hydrogeology.

GAIA Resource, Inc. is staffed by trained professional staff for hazardous waste site remediation and is associated with PH.D.s in microbiology, chemistry, and engineering on the Faculty of major universities.

Vendor Name: IT CORPORATION Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

In situ bioremediation of groundwater and saturated soil is achieved by developing a system of extraction and injection wells that deliver nutrients and oxygen and contain the plume of contaminants. The process enhances the subsurface environment such that microbial degradation of organic contamination is stimulated.

The system is enhanced by polishing the recovered water, supplementing it with Restore brand central products, and reinjecting it into the subsurface. Restore 375 is comprised of a patented blend of chemicals that provide the essential inorganic nutrients required for biodegradation of organic matter, as well as a buffer system to prevent nutrient precipitation. A second patented product, Restore 105, is a specially stabilised hydrogen peroxide solution that provides oxygen for the degradation process. This system stimulates indigenous bacteria to rapidly oxidise organic matter into innocuous end products such as carbon dioxide and water. The process is run on a continuous basis, and requires minimal operation and maintenance. When the treatment is complete, the bacterial population returns to pretreatment levels. (s0B

TECHNOLOGY HIGHLIGHTS

This technology provides an unobtrusive remediation alternative without the extensive treatment period required by pump-and-treat systems. The contamination is destroyed, therefore in situ bioremediation reduces or eliminates the owner's liability, unlike disposal or transfer to another matrix such as activated carbon. IT has used this technology to return groundwater to drinking water standards. IT has provided this technology at a savings of 60 percent, compared to pump-and-treat technology.

TECHNOLOGY LIMITATIONS

The major limitation this technology has is the transport of nutrients and oxygen in the subsurface. Interferences such as soil mineral content and the hydraulic conductivity of the formation can limit the feasibility of in situ bioremediation. In addition, the soil sorptive capacity can limit the achievable treatment target level for soil by rendering the contamination unavailable for microbial degradation. Lastly, additional organic substrates that are difficult to deliver to the subsurface environment may be required for the more complex contaminants such as substituted organic compounds.

This technology is also limited to treating contaminants in the aqueous phase. For this reason, it is usually less cost-effective than other remedies for treating free-phase product.

OTHER COMMENTS ON TECHNOLOGY

IT Corporation has successfully used this technology to obtain closure on more than six sites. IT Corp. is prepared to provide all services and equipment required to conduct in situ ground water bioremediation.

Vendor Name: MICROBIAL ENVIRONMENTAL SERVICES (MES)

DESCRIPTION OF TECHNOLOGY

Microbial Environmental Services, Inc. (MES) uses bioremediation technologies to treat groundwater aquifers contaminated with petroleum and bioreactor treatment technology for treating industrial effluents containing hazardous organic compounds. The design is based on the introduction of low concentrate nutrients and oxygen into the subsurface via infiltration galleries and extraction through a recovery well to enhance naturally occuring microorganisms. The system is a hydraulically controlled biodegredation system designed to prevent migration of the contaminants and nutrients from the treatment site. The results of biodegradation of contaminant by naturally occurring microorganisms are carbon dioxide and water.

TECHNOLOGY HIGHLIGHTS

MES, Inc. performance advantages are the result of site-specific design of the biotreatment system and the implementation of intensive quality control and optimised process methodologies. Our on-site bioremediation technologies do not result in the release of volatile organics into the air or allow the leaching of contaminants into the subsurface. Benefits unique to our microbial technologies versus other forms of non-biological remediation include quiet operation, quick and complete degradation of organic contaminants, as well as competitive price. In addition, our process uses only the microorganisms on site as the degraders.

TECHNOLOGY LIMITATIONS

MES, Inc. bioremediation technologies are not applicable to the treatment of non-biodegradable wastes; wastes containing metals only, inorganic cyanide wastes, inorganic corrosive wastes, and wastes containing radioactive materials. The technologies are also not applicable to the treatment of PCBs and dioxins/furans.

OTHER COMMENTS ON TECHNOLOGY

Scientists and engineers at MES, Inc. have applied more than a decade of knowledge and experience in bioreactor design, microbial ecology and environmental microbiology, transport phenomena, and waste management to develop and design the biotreatment technologies used by MES, Inc. Services offered for cleaning up contaminated soils and groundwater aquifers include: site characterisation and biotreatability testing, remedial design, site monitoring, and project management. Biotreatment technologies for herbicides/pesticides and explosives are in scale up/demonstration stages. MES has patents that have been applied for; some patents are still being applied for.

Vendor Name: GROUNDWATER TECHNOLOGY, INC. Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

In situ bioremediation is a method for treating groundwater and subsurface soils without excavating the impactd soils. By promoting the proper environmental conditions at the location of the contaminants of concern, the natural microorganisms in the subsurface soils, multiply and transform the contaminants into nontoxic compounds.

The techniques utilised to modify the subsurface environment include:

- Delivering nutrients to the locations of the contaminants; - Delivering a suitable electron acceptor.

Generally the nutrients and electron acceptor are delivered to the contaminated area in an aqueous phase. Water is amended with compounds such as ammonia, sodium phosphate, hydrogen peroxide, or oxygen and the solution is percolated into the subsurface soils by means of an infiltration gallery or recharge wells. At the same time, water is drawn up from barrier wells to form a hydrogeological containment zone. The water is recycled through this system in a manner designed to promote conditions suitable to bioremediation of the contaminants of concern. The process continues until the concentration of the contaminants of concern in groundwater is within the cleanup levels.

(This technology is also listed under Bioremediation - In situ Soil.)

TECHNOLOGY HIGHLIGHTS

The key advantages of this technology are:

1) It is in situ, thus, removing the need to excavate and remove hazardous material;

2) It is a destructive technology;

3) It often is less costly than alternatives such as incineration;

4) It relies on natural processes to remove hazardous compounds.

TECHNOLOGY LIMITATIONS

This technology is not appropriate to metal-only wastes, inorganic cyanide wastes, inorganic corrosive wastes, and wastes that only contain radioactive materials. The performance of this technology may be somewhat reduced for wastes containing heavily chlorinated organics. The main limitation is that the waste must be biodegradable.

OTHER COMMENTS ON TECHNOLOGY

This technology has primarily been used for petroleum hydrocarbon contamination. However, Groundwater Technology has installed full-scale systems for coal tars, wood preservation wastes, industrial solvents and chlorinated organics.

Vendor Name: YELLOWSTONE ENVIRONMENTAL SCIENCE, INC. Technology Type

________________________________________________________________________ : BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

The Biocat-II(TM) process for bioremediation - in situ ground water treats a variety of wastes including aromatic hydrocarbons and halogenated hydrocarbons. The process entails such means as control of oxidation-reduction potential, pH, salinity, temperatures, and addition of electron donor(s) and/or electron acceptor(s) to sequentially enrich in situ cultures of mircoorganisms capable of accomplishing the required biotransformations.

Injection and possibly, extraction wells are used to sequentially create in a contaminated groundwater zone, the required enrichment conditions. The microorganisms to be enriched may be those present naturally, or, if necessary, inoculation of the aquifer with other natural microorganisms may be practiced. In one embodiment, stoichiometric amounts of nitric acid, nitrate, or nitrous oxide, and/or a primary substrate such as acetate, are injected into a contaminated groundwater zone in an initial treatment step. Alternatively or sequentially, stoichiometric amounts of sulfuric acid or sulfate and/or a primary substrate such as acetate are injected into the contaminated groundwater zone. If necessary, inoculation of the zone with sulfate-reducing bacteria, such as Desulfobulbus propionicus, is practiced. Microbially generated alkalinity and/or sulfide will precipitate and immobilise heavy metals to the extent that the zone remains anoxic. If necessary, following utilisation of available or added electron acceptors (e.g., nitrate or sulfate), methane-producing microorganism populations are enriched to accomplish dehalogenation reactions. If necessary, inoculation of the zone with appropriate methanogens, such as Methanosarcina barkeri and/or Methanosarcina vacuolata is practiced. If heavy metal immobilisation is not required and further biotransformations are required, oxygen or hydrogen peroxide is injected into the contaminated zone to facilitate aerobic respiration. In some embodiments, heated water is injected into the contaminated zone to increase its temperature and increase biotransformation rates.

TECHNOLOGY HIGHLIGHTS

The process has several advantages over other biotechnologies for bioremediation, including (1) natural pH control and immobilisation of metals to protect the enriched population of methanogens, (2) conversion of the breakdown products of toxic organics to methane that can be collected and used to heat water injected into a contaminated groundwater zone to thermally enhance biotransformations, and (3) elimination of releases of toxic volatile organic compounds to the environment that can occur with pump and treat aerobic processes.

Laboratory studies by Yellowstone Environmental Science, Inc. (YES) and others have confirmed removal of the following constituents during the indicated process steps (1) denitrification: benzene, toluene, ethylbenzene, o-xylene, m-xylene, p-xylene, phenol, o-cresol, p-cresol, and carbon tetrachloride; (2) sulfate-reduction: phenol, p-cresol, and carbon tetrachloride; (3) methanogenesis: benzene, toluene, ethylbenzene, o-xylene, phenol, p-cresol, 1,1,1-trichloroethane (TCA), tetrachloroethylene (PCE), trichloroethylene (TCE), carbon tetrachloride, chloroform, bromoform methylene chloride, chlorophenols, and trichlorofluromethane (FREON 11), and (4) aerobic respiration: benzene, toluene, m-cresol, p-cresol, TCE, and vinyl chloride.

TECHNOLOGY LIMITATIONS

The BIOCAT-II(TM) process is applicable in situations in which a sequence of environments such as (denitrifying and/or sulfate-reducing and then methane-producing can be induced to occur in a zone of contaminated groundwater.

OTHER COMMENTS ON TECHNOLOGY

Yellowstone Environmental Science, Inc (YES) creates, develops, and commercialises technologies for protection of the environment and enhancement of public health. YES has licensed its technologies to Fortune 500 and smaller companies and assisted in development and commercialisation efforts. The BIOCAT-II (TM) process is a patent-pending improvement of the patented (U.S. Patent No. 5,076,927) BIOCAT (TM) process for treatment of acid mine drainage and heap leach effluents. The improvements were developed during a Phase I Small Business Innovation Research (SBIR) project funded by the Defense Advanced Research Projects Agency. Laboratory (batch) testing of key process steps conducted during that project reportedly confirmed that essentially complete removal of toxic waste constituents could be achieved. For example, the concentrations of target chlorinated hydrocarbons could be reduced to less than 5 micrograms per liter.

Additional research is currently being conducted under a Phase II SBIR grant. Current activity is focused on batch reactor experiments to develop calibrated process models. These models will be used to design bench-scale prototypes of the process. The Phase II research will continue through September 1995.

Vendor Name: WASTE STREAM TECHNOLOGY, INC. Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

Waste Stream Technology Inc. (WST) applies microorganisms (WST Bioblends) to remediate soil and water contaminated with organic compounds. Specifically, the polluted matrix is amended with bacteria which augment the rate of degradation of target pollutants (bioaugmentation), rather than rely on the stimulation of indigenous species (biostimulation). Laboratory treatability studies determine the requirements for establishing the appropriate environment for bacterial growth, as well as identifying which WST Bioblends are 1) capable of reducing the contaminant, and at what concentration, 2) in a particular matrix, 3) under specific temperature and pH conditions, and 4) associated time requirements.

The bacteria are produced in sufficient quantities using uniquely designed bioreactor systems. These systems are mobile units which promote the growth of liquid bacterial cultures. Cultures are grown to optimal concentrations using WST Nutriblends, specialised growth medias, which induce the bacteria to utilise the target pollutants as their sole carbon source for growth. Nutriblends are applied to precondition the matrix for bacterial growth. Cultures are applied to surface or subsurface soils and water on a site-specific basis. Nutrients and bacteria are distributed via tilling, and vacuum or hydrogeologic flow, ensuring the interaction between bacteria, inorganics and molecular nutrients, and the contaminants. For in situ groundwater treatment, nutrients and bacteria are injected via infiltration galleries. Extraction wells extract water to be reinnoculated with nutrients and bacteria. Bacterial, nutrient, and contaminant concentrations are determined prior to treatment, and are subsequently monitored throughout the process. (This technology is also listed under Bioremediation - In Situ Bioremediation - In Situ Soil, Bioremediation - Slurry Phase).

TECHNOLOGY HIGHLIGHTS

There are several factors reponsible for the innovative nature of bioaugmentation versus biostimulation. Large-scale, on-site production of contaminant-degrading microorganisms, predominantly bacterial species, leads to a rapid increase of bacterial populations to levels associated with optimal degradation rates. Biostimulation may be more time demanding since there is a lag time for natural selection of indigenous degraders, which may represent only a minor population. There may not be any contaminant degraders present, and the indigenous population may only be tolerant of the contaminant(s). Alternatively, the natural degraders may not be as efficient as the amended species. The bioaugmenting species are characterised with respect to their activities in varying temperture, pH, inorganic and organic conditions.

In addition, they are not pathogenic. They rapidly utilise the contaminants, directly or indirectly via cometabolism since they are applied in large numbers during a logarithmic growth phase, following induction of specific enzymatic pathways. Continuous applications result in their microbial predominance, virtually overgrowing indigenous species, overcoming the attrition rate associated with the toxic properties of many pollutants. The activities of the amended bacteria are well understood, and growth is controllable. They are tracked throughout the process using state-of-the art procedures. Growth is correlated with contaminant degradation, and metabolic products of their activities are monitored from appropriate air, water, and soil sampling. Costs are diminished by its rapidity, predictability, and technical merit.

TECHNOLOGY LIMITATIONS

Bioremediation is a biological process, and therefore is limited by factors which affect the growth and reproduction of contaminant-degrading microorganisms. These include moisture, nutrients, pH, inhibitory species and their products and byproducts, bioavailability of the contaminant(s), and most importantly a population capable of degrading the contaminant(s).

A separate but significant limitation is time. This biologicial process requires weeks to months, compared with physical and chemical processes which require only days to weeks. The molecular size and configuration of the pollutant, reduces its water solubility, and contaminant (organic and inorganic) toxicity limits the degradation. As previously stated, many of these limitations can be overcome.

OTHER COMMENTS ON TECHNOLOGY

Bioremediation applications have become far reaching. It has been effective in the remediation of mixed municipal and industrial landfill wastes, petroleum refinery by-products, petrochemcials, fuel and heating oils, hazardous halogenated chemcial solvents, crude oil in spill responses in marine and fresh water and soil. Multiple variations have been successfully used, including solid-phase (landfarming, heap, and composting), in situ (air and water treatment, sorption, vapor extraction and biofiltration), and slurry-phase. Applications have not been limited by size, with projects ranging from a few hundred to more than 20,000 cubic yards, as well as leachate treatment in excess of 100 gallons per minute. WST responds to 2 to 3 inquiries per week from VISITT users.

Vendor Name: MICRO-BAC INTERNATIONAL, INC. Technology Type: BIOREMEDIATION - IN SITU GROUNDWATER

DESCRIPTION OF TECHNOLOGY

In situ bioremediation of groundwater is accomplished through batch or continuous feed treatments using M-1000 microbial consortiums. The principle on which this technology is based is the isolation of natural bacteria that have special degradation capabilities. Each type of M-1000 bacteria augments the others to accelerate various levels of degradation. No genetic engineering has been used in the development process, and there are no spores, slime-formers, or algae involved. The microorganisms used in this process are facultative anaerobes that can work in aerobic or anaerobic conditions. The process does not require any activation time.

For in situ groundwater applications, monitoring wells, injection wells, and pumping equipment are used to deliver M-1000 bacteria augments to the groundwater and extract groundwater for augmentation, discharge, or reinfiltration.

TECHNOLOGY HIGHLIGHTS

The M-1000 process augments existing systems, such as pump and treat, or serves as part of new treatment programs. The biotreatment process is typically more cost-effective, accelerates the remedial program, and is adaptable to a broad spectrum of field conditions.

TECHNOLOGY LIMITATIONS

Certain types and levels of heavy metals can be detrimental to the biological process, as can some other microbial inhibitors such as pH, extreme temperature, and permeability/porosity of the matrix through which the groundwater travels.

OTHER COMMENTS ON TECHNOLOGY

Specific testing can be done on samples from each site to determine if bioremediation is a suitable treatment process. Testing is available from Micro-Bac International, Inc.'s research and development facilities.