ETEC is #1 in the industry for recirculation equipment and soluble bioremediation products
Our successful track record is due to our staff of environmental engineers, chemists and field managers, whose combination of education, training, and hands-on experience allows us to provide a broad range of support services. In addition to providing a variety of remediation technologies, ETEC also performs field, laboratory, and engineering services related to remediation processes.
ETEC offers an extensive fleet of recirculation and injection equipment (stationary and mobile) for soil and groundwater remediation. From pilot testing to long-term project use ETEC has a solution to fit your needs. Equipment is typically leased and includes technical support and replacements parts though out the lease term. At ETEC, we continue to expand our fleet to fit your needs.
EQUIPMENT FOR PILOT TESTING
Mobile systems for pilot testing, short-term injection, recirculation and/or flushing are available for most applications.
OXYGENATION EQUIPMENT FOR AEROBIC-OXIDATIVE REMEDIATION
Oxygen is a limiting factor for most aerobic bioremediation efforts. For example, to support the degradation of petroleum hydrocarbon compounds (BTEX, TPH, etc.), 3 times as much oxygen must be delivered for complete biological degradation. Therefore, effective aerobic bioremediation of a typical UST spill requires the delivery of large masses of dissolved oxygen (DO) to the subsurface. Unfortunately, most conventional remediation systems (i.e. air or oxygen sparging) cannot deliver enough DO to support complete degradation of the TPH mass that is present at a typical UST site.
LEARN MORE ABOUT ETEC's AEROBIC-OXIDATIVE REMEDIATION PRODUCTS
EQUIPMENT FOR ANAEROBIC-REDUCTIVE OR GENERAL RECIRCULATION REMEDIATION
A primary limitation of in-situ remediation processes (i.e. chemical oxidation, bioremediation) is the lack of contact between delivered amendments and the contaminants. Unfortunately, many pilot-scale and full-scale in situ processes are implemented using slug injections, which are often ineffective because they have minimal radius-of-influence, so they fail to maintain appropriate subsurface conditions or deliver the required mass of amendments. In order to overcome these limitations, ETEC has developed automated recirculation systems that can deliver liquid and slurry-phase substrates, nutrients, or chemical oxidants to the subsurface on a consistent, scheduled basis. The In Situ Delivery (ISD™) equipment platforms are fully automated and programmable allowing you to optimize delivery of remediation products based on your site-specific remediation needs.
Electron Donor Substrates
The ISD™ Equipment can be customized to deliver a wide-range of electron donor substrates, depending upon your choice. Substrates will be automatically mixed with the extracted groundwater and re-injected throughout the site to achieve maximum contact. The ISD™ equipment is designed specifically for delivery of ETEC’s CarbStrate™ electron donor substrate as part of our anaerobic bioremediation system, but can also be used to deliver ethyl lactate, oils, or other electron donor substrates.
Chemical oxidants (hydrogen peroxide, permanganate, persulfate) are used to oxidize a broad range of organic compounds. Because oxidant cost is very high, minimizing these costs via efficient subsurface injection is imperative. Recent studies show that slug injections of high-concentration oxidant solution are ineffective, unsafe, and can waste a significant mass of oxidant. The ISD™ equipment provides precise injection control of the volumes and concentrations of oxidants and catalysts, saving money while increasing contaminant destruction efficiency, and protects your field personnel from dangerous chemical reactions.
Surfactant Flushing and Hot Water Recirculation (utilizing one of our recirculation systems)
The efficiency of pump and treat systems over time diminish greatly, leading to extended treatment timeframes. The automated delivery of surfactants can increase the amount of contaminants captured by the existing extraction system. The ISD™ equipment can move multiple pore volumes of surfactant-amended groundwater through the site to help encourage free-product and residual contaminant recovery. Any surfactant can be used, but we recommend our non-ionic PetroSolv™ biosurfactant for enhanced contaminant recovery. Hot Water recirculation is utilized for thicker product removal (i.e. No.6 fuel oil)
PRODUCTS FOR BIOREMEDIATION
For over 25 years ETEC 's PetroSolv™ has been used for surfactant enhanced remediation to solubilize and mobilize LNAPL and DNAPL, making it easier to capture and remove from the subsurface.
Surfactant flushing is an efficient stand-alone remediation treatment or can be used as a cost-effective enhancement of other treatment approaches such as bioremediation or chemical oxidation, or part of an existing treatment system. Using surfactants in remediation increases the solubility of organic contaminants, providing a number of benefits:
Increase free-product recovery
Enhance mobility of contaminants
Improve contaminant chemical availability and improve contact between contaminants and oxidants
**Improve contaminant bioavailability for aerobic or anaerobic bioremediation
**ETEC's preferred approach.
HEAT ENHANCED BIOREMEDIATION
Remediation using Thermal Conduction, Electrical Resistance Heating (ERH) and Steam Enhanced Extraction is even more effective when coupled with bioremediation, either during heating and/or after heating as a final polishing step.
Using high energy thermal remediation to treat downgradient of a highly impacted source area can be a very costly and often not considered during the first phase of a thermal project. ETEC's recirculation systems and bioremediation products are used to address these expansive areas efficiently and cost effectively.
Landfarming applications are the easiest, most effective method of remediating contaminated soil and sediment. ETEC has completed hundreds of on-site landfarm projects via a combination of effective bioremediation products and proper soil management.
ETEC does not provide soil tilling services (we leave that to a qualified contractor), but we can provide on-site application of aerobic and anaerobic bioremediation products, and we work closely with the tilling contractor to ensure that optimum soil conditions are maintained throughout the life of a project (usually 2-4 months). Effective soil management includes monitoring and maintaining appropriate soil pH and soil moisture (extremely critical), and consistently turning and tilling the soil to maximize pore space oxygen content and ensure complete mixing and contact.
Our PetroBac™ bioremediation product bundle provide pre-activated biomass and a light biosurfactant that can be sprayed directly onto the soil matrix to achieve optimum contact and continuous “cutting” of even the most recalcitrant petroleum compounds (like heavy oils). Our Custom-Blend Nutrient™ (CBN™) blend provides required macro- and micro-nutrients for microbial functions, as well as secondary electron acceptor mass to support facultative degradation of contaminants when oxygen is absent.
Soil contaminants we have successfully treated include the following:
Diesel, Jet Fuel, and Heating Oil
Crude Oil and Bunker C
Chlorinated Solvents (anaerobic bioremediation using an electron donor substrate)
Our success is based on two factors: 1) effective bioremediation products, and 2) hard-earned field application and soil management experience. We understand how to apply our bioremediation products to achieve the proper microbial conditions, and we understand the fact that different contaminants require different bioremediation products in order to achieve fast, effective biodegradation.
Typically excavations are smaller than the size of the contaminant plume in groundwater and limitations such as buildings, roads, bedrock and utilities prevent full removal of contaminants. In these areas, enhancing biodegradation of residual contamination through the use of ETEC's bio-focused products can have significant benefits to your overall remedial efforts. For a fraction of the cost of the entire project an excavation application is almost always going to provide cost effective benefits.
Soil Bioremediation Applications
Environmental consultants conducting excavation and source removal activities at UST sites are looking for cost-effective bioremediation products they can apply to open excavation pits to stimulate biodegradation of residual contaminants in soil and groundwater.
To get results, here is what you need to know:
Aerobic Bioremediation (Oxidative Bioremediation):
Most consultants have been told by vendors that dissolved oxygen is all they need for successful bioremediation. This is fundamentally incorrect - oxygen and other electron acceptors are only one aspect of stimulating effective bioremediation. Other fundamental requirements include nutrients, a desorption agent, and the addition of hydrocarbon-degrading bacteria.
Anaerobic Bioremediation (Reductive Bioremediation):
As with aerobic bioremediation, most of the emphasis placed on anaerobic bioremediation is with the choice of electron donor substrate. Using an electron donor substrate without the use of the appropriate nutrients will limit the microbial growth. ETEC includes nutrients with its electron donor substrate to ensure that the anaerobic bioremediation process is maximized.
ETEC’s approach is to obey the fundamentals of bioremediation by adding the correct mass of electron acceptors or electron donor substrate based on an estimated mass of contaminants at the site. ETEC bioremediation products also include the correct ratio of nitrogen, phosphorous, and other nutrients to ensure limiting conditions do not occur.
ETEC can apply these products for you, or you can apply them yourself using a water truck or a small tank and pump. These products are highly soluble and can be applied in minutes so that the excavation can be backfilled without delay. Our field technicians are also available for emergency response projects and can be mobilized quickly.
EXISTING SYSTEM ENHANCEMENT
Bioremediation & Surfactant Applications
Dual Phase Extraction, Soil Vapor Extraction, Air Sparge, Oxygen Sparge, Biosparge, Pump and Treat
Air Sparge and Soil Vapor Extraction (AS/SVE) systems have been used for over a decade to volatilize and capture contaminants trapped in soil and groundwater. While effective at removing contaminants initially, the efficiency of the treatment is diminished over time. Incorporating the use of bioremediation products can greatly reduce treatment timeframes leading to significant cost-savings.
The aerobic environment created by the AS/SVE system provides an abundant supply of oxygen to support rapid microbial degradation. If the remaining components, nutrients and biological products, are added to the subsurface, rapid microbial degradation can occur. Air sparge enhancement is especially effective for less-volatile contaminants and for obtaining low regulatory cleanup concentrations.
Pump and treat and extraction type remediation systems were one of the first remediation technologies developed and implemented. Contaminated groundwater and vapor is extracted from throughout the site, treated above-ground and discharged. While effective at containing migrating contaminant plumes, contaminant mass removal diminishes significantly over time and can lead to very long and O&M intensive cleanups. Enhancement of existing or proposed pump and treat systems can greatly increase contaminant removal efficiency and significantly reduce overall remediation duration and cost.
Pump and treat or multi-phase extraction systems can be enhanced by incorporating the following:
ETEC’s engineering staff can help you design the most effective addition to your existing or proposed remedial system. Often existing infrastructure can be used, leading to significant cost-savings.
Our aerobic and anaerobic bioremediation products can be utilized depending on the contaminant of concern, to enhance your dual phase extraction, soil vapor extraction, air sparge, oxygen sparge, biosparge, and bioventing treatments.
DIRECT INJECTION (Injection Wells or Direct Push)
For sites where permanent treatment systems are not desired, necessary, or feasible, periodic direct injection of bioremediation products can be a cost-efficient cleanup method. ETEC's bioremediation products can be injected into any available wells including recovery, air sparge, soil vapor extraction, and injection wells.
Injection via direct-push points can be used for site-wide distribution or hot-spot treatment.
The major limitation with most bioremediation products is that they need to be applied as a slurry or are viscous. This leads to minimal distribution and fills the soil pore space. ETEC’s bioremediation products are 100% soluble to allow for increased distribution and easy application.
Direct Injection Benefits
Minimal site disturbance
Infrastructure, equipment and O&M cost-savings
Increased distribution compared to direct injection of slurry-phase or viscous products
As with any remediation effort, bioremediation product volumes must be based on the contaminant mass present in the subsurface. ETEC engineers can help you determine the appropriate product volumes necessary along with recommendation for application. Direct injection services are also available from ETEC or our partner remediation service contractors.
Ask about our mobile injection systems or how we can help support you and your local contractor.
ETEC has utilized many different chemical oxidation processes via direct injection and groundwater recirculation:
CHEMICAL OXIDATION - BIOREMEDIATION
In Situ Chemical Oxidation (ISCO) has been shown to be a very effective remedial alternative for a broad-range of petroleum, PAH, and chlorinated solvent contaminants. ETEC improves upon the typical slug injection of chemical oxidants by utilizing groundwater recirculation. The groundwater recirculation approach enables us to deliver the appropriate mass of chemical oxidants/catalysts to the subsurface and to achieve a greater degree of contact with the contaminants than what would be possible with a typical slug injection.
Selecting the most appropriate chemical oxidant for a particular contaminant is as critical as selecting the right delivery system. ETEC has utilized many different chemical oxidation processes in combination with groundwater recirculation. Before implementation of these methods, ETEC recommends conducting bench-scale tests with impacted media from the site. Many factors affect chemical oxidation (ex. type of catalyst, concentrations of oxidant, natural organic material, etc.), and ETEC can conduct thorough bench-scale testing to evaluate different concentrations of oxidants and metal catalysts that will provide you the most cost-effective approach prior to application at the site.
The most common chemical oxidant used is hydrogen peroxide, which requires the use of a metal catalyst to generate hydroxyl radicals capable of oxidizing organic compounds. Typical catalysts are ferrous/ferric iron or a chelated metal compound. The hydroxyl radicals generated from this method have a very short half-life in the subsurface because they are highly reactive with all organic material and carbonates. This characteristic makes this method more amenable to source zone or hot spot treatment, and not so favorable for remediating large areas due to its limited transportability.
This oxidant has characteristics that are very favorable for in situ remediation. Specifically, it is highly soluble and more stable in the subsurface than hydroxyl radicals, providing a high degree of transportability from the injection points. A metal catalyst or heat is required to create the sulfate radicals capable of oxidizing a wide-range of organic contaminants. Its low cost and high solubility allows a user to deliver the appropriate total mass of persulfate to the subsurface without incurring significant cost or labor in the field.
Combination of Hydrogen Peroxide and Persulfate
Academic research and ETECs experience have shown that using hydrogen peroxide in combination with persulfate provides the most effective chemical oxidation method. This method still requires the use of a metal catalyst to generate the hydroxyl and sulfate radicals. Initially, the metal catalyst solution is injected into a well that is then followed by a persulfate solution, and then a peroxide solution. This approach delivers the catalyst ahead of the oxidants so the reaction will occur where the iron solution is. The persulfate is injected ahead of the peroxide because the heat produced from the peroxide reaction will increase the reactivity of the persulfate. Since persulfate is more stable it will linger in the subsurface until the rapidly reacting peroxide is injected. This method has been shown to effectively oxidize PAHs, some PCBs, chlorinated solvents, and petroleum hydrocarbons.
This oxidant has been shown to be the most effective with chlorinated ethenes, and less effective on aromatic compounds. Permanganate oxidizes contaminants via an electron transfer reaction, and not via a free radical like Fenton’s. It is the most stable oxidant and can reside in groundwater for long periods of time if no reaction occurs. This ability allows it to penetrate tighter soil types (i.e. silt or clay) where other oxidants fail to achieve contact. When permanganate reacts with a contaminant it produces manganese dioxide that is insoluble in water and forms precipitants in the porespace. This can significantly reduce the effective porosity in the saturated zone, possibly limiting future injections.
PROJECT PLANNING & DESIGN SUPPORT
ETEC engineers help with the planning of your next remediation project. With extensive experience with a wide-range of remediation technologies, ETEC can offer a number of recommendations to help ensure a successful project. Our engineers will examine the available data and work with project planners to make decisions on feasible technologies, infrastructure placement, suitable equipment, sampling plans, etc.
ETEC technicians have extensive field experience with a variety of different remediation applications. Services include equipment installation, start-up, O&M and site injection/application services for in situ bioremediation and chemical oxidation projects. Our field staff possess the necessary safety training and will ensure the project operates smoothly.
DATA EVALUATION AND INTERPRETATION
Provided as part of most ETEC projects often at no additional cost, ETEC staff provides evaluation of data collected. Our extensive education and experience in these areas are valued assets to our clients and customers. ETEC will provide an in-depth analysis of the site data (pre- and post- remediation) for inclusion in regulatory documents. We can also educate key personnel on the important details of data interpretation if desired.
ETEC teams with licensed, accredited laboratories that specialize in microbial plate count assays and inorganic nutrient analyses. These analytical services are useful for clients that are evaluating the feasibility of bioremediation projects, optimizing active remediation projects or for inclusion in regulatory documents for a complete view of site conditions.
When a contaminant release occurs, whether it is a UST or transmission pipeline, a fast response is critical to a successful cleanup. ETEC has warehouses located strategically within the continental United States and can ship product quickly. Additionally, ETEC is available 24/7 to help with application rates and methods for our bioremediation products. Our efficient bioremediation product application method will not interfere with excavation and back-filling activities, while supporting long-term biological degradation of the remaining contaminants in the soil and groundwater.