HC-2000 (HC2) is a Green Sustainable Technology product. HC2 restores the environment by accelerating natural systems (heterotrophic bacteria) to degrade petroleum and solvent based contaminants. HC2 is non-toxic and removes toxic contaminants with minimal economic disruptions to business and generally cost less than other remedial technologies. Remtech's Bioremediation Design Optimization Primer with HC-2000 is presented here. Remtech's Biopile Bioremediation Design Optimization Primer with HC-2000 is presented here.
When treatment is complete, native conditions are restored. Complete mineralization results from a consortium of native microorganisms working together synergistically. Cometabolic activity (enzymes generated by an organism growing at the expense of one substrate) can also transform a different substrate that is not associated with that organism's energy production, carbon assimilation, or any other growth process - degradation of a compound only in the presence of other organic material that serves as the primary energy source (11).
Multiple bacteria populations found in nature provide the mechanisms to break down petroleum compounds to CO2 and water that is not possible with a single bacterial strain. Many organic contaminants will serve as a substrate. However, for some hazardous chemicals, another substrate is necessary. The compound targeted for degradation may be at concentrations below that necessary for good biological response for bioremediation. The addition of a primary substrate (contained in HC-2000) supplies additional energy. When another energy and carbon source is made available to stimulate biological growth, it becomes the primary substrate and the target compound to be degraded is the secondary substrate.
Heterotrophs have been demonstrated to be effective degraders of a variety of hazardous and non-hazardous wastes including petroleum hydrocarbons, chlorinated solvents, and other pollutants. A myriad of degradation data was generated in the 1980s during research on land farming of hazardous wastes (1). Ross McKinney in his book Microbiology for Sanitary Engineers states ... the best source of micro-organisms is soil. The soil can furnish all the microorganisms ever needed in waste disposal. My advice to all sanitary bacteriologists who seek a special culture is to look under their feet; the supply is inexhaustible (2). HC-2000 targets native heterotrophs that control the bioremediation process.
Heterotrophic degradation is limited by enzymes, co-factors, nutrients, electron donors, biosurfactants, and the proper environmental conditions that accelerate biochemical reactions. Natural attenuation can take years and generally reaches asymptotic concentrations due to insufficient nutrients or inadequate environmental conditions. HC-2000 supplies the limiting factors outlined above and reduces degradation times to months or longer periods for more resilient compounds.
HC-2000 is a non-toxic aerobically fermented natural organic product that is readily assimilated and eliminates long lag reaction/acclimation periods. HC-2000 can be applied under various environmental conditions (aerobic, facultative, methanogenic, anaerobic).
HC-2000 (developed by Remtech in 1998) degrades, cleans, disinfects, desorbs, reduces vapors, odors from fuels, oils, lubricants, and chlorinated and non-chlorinated solvents in soils, ballast, gravel, surface water, groundwater, and other media. HC-2000 has been used successfully on over 400 cleanup sites during the past 17 years.
HC-2000 bioremediation accelerator product is designed to work on freshwater applications and refined fuels and solvents that are not addressed by EPA’s NCP List of saltwater approved crude oil remediation and cleaning products. HC-2000 is up to an order of magnitude less toxic to aquatic organisms than most of the NCP products.
HC-2000 is particularly cost-effective where: service or business interruptions need to be minimized; access is limited; areas are environmentally sensitive; or sites are geotechnically, hydrologically or structurally sensitive or unstable.
HC-2000 Multi-Media Applications
Soil Treatment - treats surface soil passively (via topical or gravity feed systems for soil depths up to 3 to 5 ft) or actively (in combination with biovent/injection & biosparge/multiphase extraction systems for depths exceeding 5 ft).
Ballast & Gravel Treatment (Railroad Ballast, Gravel at Power Substations & Tank Farms) - Gravel and/or ballast can be treated with HC-2000 at railroad mainline and siding tracks, power substations, and in above ground storage tank secondary containment areas. HC-2000 is particularly effective in railroad ballast (that functions like a trickling filter with elevated baseline heterotrophic bacteria plate counts). In place treatment minimizes rail or power service interruptions and disturbance of grounding and cathodic protection systems.
Groundwater Treatment - treats groundwater insitu passively (infiltration galleries, biofences) or actively (reactor trenches, sparge wells, and total fluids extraction wells).
Surface Water Treatment - removes sheens by lowering surface tension and allowing petroleum hydrocarbons to come in contact with particulate born bacteria for degradation. Removes light sheens and odors almost immediately and desorbs fuel from banks, leaves, limbs, and other organic matter. Degrades solution phase contaminates in aerobic, facultative, and anaerobic environments.
Pavement & Surface Cleaning - cleans/removes oils and solvents from asphalt, concrete, metal surfaces, and parts. Accelerates degradation rates of rinsates.
Sediment Treatment - desorbs flammable/combustible fuels and solvents from sediment in sewers, retention ponds, stream/river beds, and storage tanks. Flushing systems with HC-2000 accelerates solvent removal/desorption, degradation, and lowers flammable vapor concentrations. Insitu treatment methods minimizes erosion.
Solids & Sludge Breakup - breaks up sludge in digesters, sludge pits, septic tanks, and solids buildup in ASTs and USTs.
Forrest Canopy, Vegetation, River Banks, & Wildlife - elutriates fuels and solvents from leaves, foliage, sod, etc. to minimize interference with photosynthesis and minimizes loss of foliage. Rehabilitates flora & fauna from oil exposures. Accelerates degradation of wash residues.
Wastewater Treatment - accelerates biological degradation in oil/water separators, truck and car washes, parts washing, septic tank systems, and conventional biological wastewater treatment systems.
Vapor & Odor Control & Disinfection - HC-2000 kills pathogenic and odor causing bacteria, reduces vapor pressure of volatile compounds, and activates bacterial odor degrading microorganisms.
Tank Cleaning - Removes petroleum hydrocarbons and solvents from above ground and underground storage tanks.
Technology Selection Factors
Environmentally Sensitive Areas - food quality natural components in HC-2000 accelerate bioremediation in environmentally fragile areas such as wetlands, marshes, beaches, national parks, dunes, nature preserves, and forests without adverse environmental impacts on flora or fauna. HC-2000 synergistically accelerates bioremediation in the rhyosphere (root zone), and organically enriched and microbial diverse environments.
Structurally Sensitive/Restrictive Areas - treats soils and groundwater under buildings, around footings & building foundations, utilities, old fragile sewer systems, and grounding & cathodic protection systems.
Geotechnically Unstable or Erosion Sensitive Areas - treats drainage ditches, stream beds, river banks, and highway right-of-ways while minimizing erosion and adverse environmental impacts.
Security Sensitive Facilities - in access restricted areas, applications can be made quickly with minimal disruptions at airports, military and penal installations.
How Does HC-2000 Work?
Native heterotrophs are ubiquitous in the environment and are found in soil, water, groundwater, and waste in aerobic, facultative, methogenic, and anaerobic zones. Indigenous (insitu) bacteria are the predominant degraders in soil, groundwater, surface water, railroad ballast, gravel, and saltwater.
Numerous publications conclude that very little scientific data demonstrates that enhanced degradation (microbial addition or bioaugmentation) works on full-scale cleanups. According to peer reviewed literature, bioaugmentation appears to have little benefit for the treatment of spilled petroleum hydrocarbons in the environment. Microbial addition has not been shown to work better than nutrient addition alone in many field trials (10). Biostimulation has been proven to be a promising tool to accelerate and enhance the natural attenuation process.
Native soil populations capable of degrading petroleum hydrocarbons have been reported to range from 10 to 20% of all soil heterotrophic bacteria. Soil particles containing heterotrophs are found in lower concentrations in groundwater and surface water (2 x 106 cells/ml) than in soil (2 x 107 cells/gm) (11), albeit provide the metabolic and synthetic activity to digest petroleum hydrocarbons. Approximately 67% of all bacteria in groundwater sediment are attached to the silt and clay fraction, though this sediment fraction may account for a small fraction of the total sediment by weight.
A. Phase 1: Locate, Contain, and Monitor Mobile phase
- Monitor leachates and soil degradation targets (visual observation of stormwater runoff - no sheens), sample ballast fines and downgradient soil and leachate for total petroleum hydrocarbons. Supplemental water may be required to maintain moisture levels at 70% of field holding capacity.
- Apply HC-2000 per label instructions and adjust for site conditions.
- Repeat until regulatory limits, risk based closure, or until natural attenuation can reach regulatory limits.
- Remove/close leachate control systems.
- Close HC2 injection systems.
- Determine site access and available site service interruption time, ie, track time, business interruptions, environmental receptors, sensitive environments and structures, and cleanup and risk based targets
- Locate contamination and mobile phase pathways. Look for short circuits, i.e., sewers, swales, drains, backfill, utilities, streams using test pits, monitoring wells, geoprobe points
- If mobile phase present, install containment or free product migration monitoring system. Install leachate/migration control systems (straw bale filtration dams, collection trenches, pits, drainage tiles & sumps, or temporary detention pools). For track applications, instal leachate control near toe of ballast and/or in drainage swales. Apply HC-2000 followed by oxygen saturated water to increase penetration, moisture, and oxygen.
- Protect structural integrity of track, grounding, and cathodic systems - Do not disturb ballast below ties or within a 45% slope of tie edges.
- Monitor and contain free product movement.
C. Phase 3: Degradation Phase
- Remove mobile phase or saturated soil/solids hot spots and HC2 injection method and grid.
- Apply HC-2000 (followed by water chase to accelerate removal of mobile phase and assist with product desorption. Bound contaminates account for over 60% of contamination. Fuels may become mobile as they are desorbed and broken down into shorter hydrocarbon chains.
- Ballast Treatment – Apply HC-2000 topically followed by a water chase or through injection probes. Fouled ballast - mixing or agitation enhances HC2 delivery and treatment. Pressurized water (3,000 to 5,000 psi) or a cribbing bucket loosens ballast next to ties.
- Repeat HC-2000 applications until mobile phase dissipated.
Activation & Stability of HC-2000
HC-2000 has a shelf life that exceeds five (5) years (as long as it is stored in its concentrated state and at temperatures below 120oF). HC-2000 is activated when it is mixed with water according to the contaminated matrix and applicable dilution ratios. Diluted mixtures of HC-2000 have a shelf life of a couple of weeks and should be utilized as soon as possible after mixing with water.
Regulatory Approvals
Regulatory authorities frequently favor (and generally quickly approve) the acceleration of natural degradation processes with a Green Sustainable Technology as apposed to addition of foreign microbes or toxic materials into the environment. Stimulating natural biochemical processes reduces the possibility of toxic by-product formation and allows multiple native species (operating under a variety of environmental conditions) to reduce contaminates to minimum levels. When treatment is complete, native conditions are restored.
HC-2000 has been approved by Georgia, Florida, and other states for the treatment of soil and groundwater on a case -by-case basis. No specific approval is required for soil applications in Georgia. Georgia frequently only requires three (applications of HC-2000 to soil without performance sampling to complete a cleanup.
HC-2000 Benefits
HC-2000 is a Green Sustainable Technology. HC2 restores the environment by accelerating natural systems (heterotrophic bacteria) to degrade petroleum and solvent based contaminants. HC2 is non-toxic and removes toxic contaminants with minimal economic disruptions to business and generally cost less than other remedial technologies. When treatment is complete, native conditions are restored.
Other remedial technologies may leave residual contaminants that require additional treatment. These technologies include; pump and treat, soil venting and air sparging, and total fluids extraction. Why not use a technology that can finish the job?
Site remediation costs with HC-2000 typically range from $15 to $225/cy of contaminated media. Costs are site specific and are affected by the type and amount of contamination, local geology, volume of contaminated media, and contaminant location. HC-2000 performs best in formations where adequate communication and mass transfer are present or can be established.
HC-2000 is non-toxic, non-allergenic, and contains food quality ingredients. Accelerating the natural degradation process (Biostimulation) with HC-2000 is generally received favorably by regulatory authorities and the general public. Native heterotrophs are already acclimated and distributed in the environment. All that is required is to deliver HC-2000 to the degraders and provide adequate environmental conditions. When treatment is complete, native conditions are restored.
HC-2000 goes right to work by energizing native heterotrophs. Chemical oxidization with permanganate, peroxide, and ozone frequently oxidize materials other than target contaminants, i.e., a significant mass of reagents are wasted. Chemical oxidization and bioaugmentation may form toxic by-products that are not normally associated with cometabolic native biochemical reactions.
Oxygen and hydrogen release compounds singularly introduced generally rely on passive slow release mechanisms and depend on advection and dispersion to transport the reagent to the contaminant. Limiting nutrient deficiencies, enzymes, and co-factors are not addressed. Adsorbed and soil pore bound contaminates are only addressed by sufficient concentration gradients to draw reactants to contaminants. HC-2000 provides contaminant desorption with biosurfactants that is generally more effective than concentration gradients. Aggressive pulsed reagent injection (used with HC- 2000) generally provides better mass transfer and mixing.
HC-2000 is easily assimilated by native bacteria without a lag time. Commercial fertilizers and synthetic surfactants may initially inhibit microbial degradation. Nutrient and carbon sources such as molasses, sugars, and vegetable oil need to be broken down further prior to assimilation by microbes. Organic nitrogen and proteins (contained in HC-2000) are a preferred source of nitrogen over nitrates, ammonia, and other compounds containing nitrogen.
- Hazardous Waste Land Treatment, Environmental Protection Agency, Solid Waste & Hazardous Waste Research Division, Cincinnati, Ohio, April,1983.
- McKinney, Ross, Microbiology for Sanitary Engineers, McGraw-Hill Book Company, Inc.,1962.
- Suthersan, Suthan S., Natural and Enhanced Remediation Systems, Lewis Publishers, 2002.
- Suthersan, Suthan S., Remediation Engineering, CRC net Base,1999.
- Ryckman, Mark D., et. al., Enzyme helps Remediate at Lightning Speed, Soil and Groundwater Cleanup Magazine, February - March 1997.
- Ryckman, Mark D., et.al., Cut Project Life Cycle Costs, Soil and Groundwater Cleanup Magazine, January - February 1996.
- Enhanced Bioremediation with HC-2000, Remtech Engineers News Letter, Vol. 6, December, 2002.
- HC-2000 Multi-Media Applications, Remtech Engineers News Letter, Vol. 9., November, 2004
- Remtech Engineers, Confidential Client Project Report Files,1997- 2016.
- Venosa, A., Literature Review on the Use of Commercial Bioremediation Agents for Cleanup of Oil-Contaminated Estuarine Environments, USEPA, National Risk Management Research Laboratory, Cincinnati, OH, July, 2004.
11. Cookson, John T., Bioremediation Engineering - Design & Application, McGraw-Hill, Inc., 1995.
12. Nikolopoullou, M., Kalogerakis, N., Enhanced Bioremediation of Crude Oil Utilizing Lipophilic Fertilizers Combined with Biosurfactants and Molasses, Marine Pollution Bulletin 56 (2008) 1855-1861., Elsevier Ltd, 2008.
SIMPLIFIED
MICROBIAL AEROBIC WEATHERING/MINERALIZATION
OF PETROLEUM HYDROCARBONS
Serving Georgia, Tennessee, Alabama, North Carolina, South Carolina, and Florida
B. Phase 2: Remove/Desorb Mobile Phase
References