AEROBIC PROCESSES (chart) (with oxygen) or anaerobic processes (without oxygen) occur naturally in the subsurface. Enhanced bioremediation uses an understanding of site specific geochemistry and naturally occurring microbial processes to optimize site conditions. Enhanced bioremediation improves the environmental conditions for the microbial degradation of specific contaminants by adding an electron acceptor such as oxygen, which is frequently the limiting factor of the natural process.
AEROBIC BIOREMEDIATION (photo of oil and microbes in petri dish) = microbes (subsurface) + food (hydrocarbons) + electron acceptor (oxygen). The oxygen accepts the electron as part of the microbial cellular respiration process. The photo above shows crude oil being degraded by aerobic microbes in a laboratory cell culture dish.
EBS SERVICES AND TECHNOLOGIES
Bench Testing and Feasibility Studies
EBS has performed dozens of feasibility studies for enhanced bioremediation, in-situ chemical oxidation (ISCO), in-situ chemical reduction (ISCR), geochemical stabilization, and free product extraction using biosolvent flushing.
Odor Assessment and Mitigation
EBS designs and implements active and passive odor assessment projects which include interviews, a site inspection, an evaluation of applicable chemistry, breakdown products and wastes related to onsite processes, and waste storage. Odor profiling is obtained using thermal desorption profiling to clearly identify organic compounds which can cause odors. Mitigation methods, best management practices, and employee training, if needed, can be designed based on sampling results. The 7 to 14-day passive samplers provide data in micrograms per cubic meter (ug/m3) or parts per billion vapor (ppbv) which are time-weighted average concentrations. In many cases, the passive samples give a more representative assessment of site conditions than a one-time sample result. Passive samplers provide both accurate and precise data. Organic chemicals associated with nuisance and landfill odors can be identified using these sampling methods.
Fragrance profiles for raw materials, everything from hops and malts for beer brewing, coffee and tea to air fresheners, perfume and wine aroma profiles are performed by EBS using thermal desorption profiling. Specific organic compounds are identified by the analytical process. Fragrance profiles can detect tainted corks for wine makers or low quality raw ingredients such as hops for brewers. Separation capacity of the analytical equipment allows for essential oils in a variety of personal care products to be distinguished and identified.
Identification of Illicit Drug Labs
EBS uses analytical testing methods to detect low-concentrations of drug manufacturing residues in indoor air, plumbing-sewer air, and in confined spaces such as vehicle passenger cabins or trunks. Specific organic compounds detected and the association of chemicals can better delineate the differences between the following clandestine production of illicit drugs:
Phenyl-2-propanone (P-2-P), cocaine, heroin, methaqulone, methamphetamine, phencyclidine, lysergic acid diethylamide (LSD), and other drugs.
Sewer Air Testing
EBS performs sewer air testing to identify possible human exposure related to vapor intrusion issues in buildings.
[Pseudomonas (microbe)] Enhanced bioremediation relies on general availability of naturally occurring microbes to consume contaminants as a food source (petroleum hydrocarbons in aerobic processes) or as an electron acceptor (chlorinated solvents). In addition to microbes being present, in order to be successful, these processes require nutrients (Carbon: Nitrogen: Phosphorus equals 100:10:2 or 100:10:1). EBS evaluates geochemical and redox conditions in aquifers as well as microbial counts for biofeasibility studies (aerobic, anaerobic, and co-metabolic). EBS will perform nutrient calculations as well as provide the design and liquids for site-specific nutrient mixes. Sometimes, the microbes necessary to provide exude the proper enzymes are not present in volumes capable of reasonable degradation rates. In those cases, EBS works with laboratories to develop microbe cultures for specific contaminants, such as MTBE, PCE, TCE and other compounds.
Laboratory Bench Scale Services
Commonly overlooked, bench testing provides some of the most important site-specific information about the likelihood of success or failure of an in situ remediation project. EBS performed dozens of bench tests for in situ chemical oxidation (ISCO) (bench tests for Fenton's Reagent, permanganate, persulfate, ozone, and others), enhanced bioremediation (microbiological feasibility studies and microcosm studies) and metals stabilization for numerous consulting companies. These tests are a way to optimize reactant chemistry in the laboratory rather than in the field. In addition, EBS provides bench tests for process treatments for environmental equipment to verify successful results and proper designs.
In-Situ Chemical Oxidation
EBS designs and implements a variety of in situ chemical oxidation (ISCO) processes for soil and groundwater remediation. EBS designs and provides field oversight for the high-pressure injection of liquid or solid chemical oxidants such as the hydroxyl radical (Fenton's Reagent), hydrogen peroxide, persulfate, potassium, sodium and calcium permanganate, percarbonate, and persulfate to greatly accelerate the complete destruction of petroleum hydrocarbons, chlorinated solvents, MTBE, BTEX, PCBs, PCPs and other organic chemicals. Delivery pressures for liquid oxidants include well and filter gallery trenches (30 to 40 psi), moderate pressure injection rods (200 to 600 psi) to high pressure (3,000 to 5,000 psi) lances. Ozone, a gas, is also used for in-situ remediation in a variety of delivery systems. EBS oversees the installation of the oxidants with proprietary injection and pumping technologies in specialized sparge points or treatment trenches. Ozone can be injected at low pressure (less than 15 psi) or higher line pressures (40 to 75 psi) for in situ applications. Safety design is an important element of any EBS-designed injection project.
• Groundwater Modeling services
• Design Considerations For In-Situ Chemical Oxidation Using High Pressure Jetting
• In-Situ Chemical Oxidation Using Jetting Delivery
• List of organisms destroyed by Chemical Oxidation
Ozone Treatment Packages
Ozone (O3) is a powerful gas phase oxidizer that can be used to treat volatile organic compounds. Ozone must be generated on-site and the gas cannot be stored; therefore all the ozone gas that is generated must be injected into the subsurface or destroyed using an ozone destruction unit on the ozone generator. The ozone gas can be bubbled into closely spaced injection ports that release the bubbles into the aquifer for remediation. The smaller the bubbles, the more surface area and the faster they can travel through small pore spaces. Pumping the ozone gas through specially designed ozone diffusers can produce micro-bubbles. Advanced oxidation processes refer to when ozone is catalyzed or enhanced by ultra violet light, hydrogen peroxide or other oxidizers, to increase the power of the ozone by producing more hydroxyl radicals. Treatability testing in the laboratory can evaluate the cost benefit of the different ozone enhancements prior to mobilizing into the field.
In-Situ Metals Geochemical Fixation or Stabilization
EBS designs and injects liquid and gas reducing agents to immobilize toxic soluble metals such as lead, arsenic, chromium (VI) also called “hexavalent chromium”, cadmium, nickel and other metals using geochemical fixation. The treated metals become insoluble in the process, reducing the need for expensive excavation and disposal. EBS uses sulfur dioxide (gas) as well as the following liquids: calcium polysulfide, sodium metabisulfite and ferrous sulfate in a proprietary jetting technology. Safety design is an important element of any EBS designed injection project.
• Metals Stabilization Using Geochemical Fixation
• PowerPoint - Hexavalent Chromium Remediation (click screen to advance presentation)
• Chromium (VI) Handbook
• Chromium (VI) Attenuation Study
EBS does not sell remediation equipment, except for the inVentures Technologies, Inc. gas infusion equipment. Other companies, such as Remediation Shop www.remediationshop.com sell a variety of remedial equipment and license remedial processes. For more information, please contact: Kevin Pope, 800-794-1789). Remediation Shop installs and distributes a variety of groundwater and treatment water and soil remedial equipment such as ozone generators, thermal oxidizers, oil water separators, emulsion-splitting plants, evaporators, equipment and chemical storage, sewer treatment discharge plants, car/truck wash systems, industrial wash wastewater recycling systems, advanced oxidation systems, fluidized bed bioreactors, and grease treatment systems.
EBS works with consultants who work with small wineries (<30,000 cases per year) and larger ones who are required to meet water treatment goals for waste water used in the wine making process and equipment washing process. Until relatively recently, this segment of industry has not seen much regulatory oversight, however, water regulators are now focusing on wineries. This water typically has 3,000 to 5,000 mg/L biological oxygen demand (BOD). EBS has developed a modular approach that is flexible for wineries as well as cost effective for discharge to land through irrigation or discharge to a sanitary sewer. Typical waste discharge requirements for discharges of winery waste are available in the link below.
• Winery Discharge Requirements
EBS provides bench testing, field testing as well as the designs and oversight for the field implementation by others of a variety of remedial processes.
• Cold Mix Asphalt Process for soils and sludges (for metals, hydrocarbons, solvents and pesticides); and
• High Pressure Biosolvent Flushing Process for Groundwater (for heavy oils, diesel, motor oil, crude oil,
hydraulic oil, PCBs, PAHs).
Soil and Sludge Recycling Process
Cold mix asphalt (CMA) is a remedial process that recycles sludges and soils contaminated with petroleum hydrocarbons, heavy metals, chlorinated solvents and pesticides/herbicides into a useful product: asphalt. The asphalt can be stored for 6 months or more, and can be used for parking lots, bike paths, hiking trails, berms and other uses.
COLD MIX ASPHALT
Free Product Removal Technologies
EBS has developed or worked with two in-situ free product removal processes that are performed by others, in which EBS provides technical oversight. These include the High Pressure Biosolvent Flushing Process and the CO2 Saturated Water Injection Process.
High Pressure Biosolvent Flushing Process
In the laboratory, an environmental-friendly biosolvent for the removal of heavy to moderate weight petroleum hydrocarbons, such as diesel, motor oil, hydraulic oil, PCBs and crude oil has been developed. It has been approved by the US EPA for use in off-shore and river oil spills. EBS uses environmentally friendly, naturally occurring surfactants for acceleration of in-situ remediation of free product (both hydrocarbon and chlorinated solvents). By generating micro-droplets, the free product is broken down from one large liquid area into billions of micro-droplets. This transformation increases in surface area, allowing for more rapid degradation by both chemical oxidation and enhanced bioremediation.
TYPES OF PROJECTS
Since 1989, EBS has worked on hundreds of small and large projects in the following industries or settings:
• EBS projects are usually brought in by consultants, working on a variety of settings, including many industries, including the refining and distribution of petroleum and oils, dry cleaners, transportation, marine transportation companies and rental companies as well as public sector owners such as cities, counties, the Federal government, including the military.
• Types of Properties: EBS has worked on projects at manufacturing, industrial and commercial properties, for owners and consultants whose clients represent both the private and public sectors.
Contact: James A. Jacobs, P.G., C.H.G., firstname.lastname@example.org; cell: 510-590-1098
Enhanced Bioremediation Using Gases and Liquids
Although bioremediation is generally a slow process, taking a few months to start to see results, it can be an effective and low cost remediation strategy, usually in the residual remediation management zone (Zone 2). If the source of contamination has been removed using excavation, two-phase extraction (or soil vapor extraction for the soil source zone), chemical oxidation (ozone, Fenton’s Reagent, persulfate, etc.) or other method, enhanced bioremediation is a good choice to reduce the residual concentrations of petroleum hydrocarbons to levels that will allow case closure. Enhanced bioremediation can be used to treat some source areas, particularly for chlorinated solvents, when using anaerobic processes (reducing compounds such as lactate compounds and fermentable soybean oils). This technology can be used to enhance existing pump and treat systems, reducing remediation time significantly.
Bench Testing - EBS performs biological and chemical laboratory bench biofeasibility evaluations for all contaminants and microcosm studies (growing the microbes on a particular substrate) for many projects. These planning activities are highly recommended before starting any in-situ enhanced bioremediation program. Chlorinated solvents such as tetrachloroethylene (PCE), trichloroethylene (TCE), and 1,4-dioxane, for example, can be treated using in-situ treatment methods.
Enhanced Anaerobic Bioremediation
Fermentable Carbon Substrates
The anaerobic fermentation process can be used for dehalogenation of chlorinated solvents as well as lowering the redox potential of the aquifer to encourage the precipitation of heavy metals. This approach is a well understood and documented method to remediate many chlorinated solvents (such as PCE and TCE), perchlorate, nitrate, TNT and some heavy metals, such as chromium in soil and groundwater. EBS works in the laboratory and in the field with a variety of rapid, immediately bioavailable (hydrogen gas) to moderate (lactate) to slow and long-lasting electron donors (edible soybean oils) for a full range of carbon substrates to encourage microbial degradation and abiotic reduction processes to degrade a variety of chlorinated solvents, heavy metals, perchlorate, nitrates and other pesticides/herbicides. Fermentable soybean oils can be made into a micro-emulsion, which allows for better migration through the pore throat openings of the aquifer.