About JRW
JRW Bioremediation is a leader in the development of environmentally-friendly products used to remediate contaminated soil and groundwater based on innovative patented technology involving the anaerobic degradation of contaminants in the environment. Our mission is to supply "green" products to our clients around the world, in order to provide them with an accepted and economically sound remediation technology that will increase the quality of life and economic vitality of the community at large.
JRW’s products are being used by our clients to clean up groundwater contaminated with chlorinated solvents, perchlorates, acid mine drainage, and heavy metals. Our products have been deployed at U.S. Department of Energy sites and military installations, Superfund sites, mining sites, Brownfields, industrial sites, private chemical plants, and dry cleaners across North America and Europe. To date, our products have been used at over 300 projects in nearly every state in the US, including Hawaii and Alaska.
JRW’s products have saved our clients millions of dollars every year by reducing the time necessary to clean up contaminated sites (in many cases reducing the project length by years and in some cases decades), and by reducing overhead costs associated with maintaining and monitoring mechanical remediation installations. At JRW, we strive to provide our clients with economically-feasible alternatives to costly remediation options.
WHY BIOREMEDIATION
Cost
Performance
Flexibility
COST
The overall cost of bioremediation is generally significantly lower than other types of remedial approaches. The classic excavation, removal, and backfill option can easily cost over $50 per cubic yard, not including disposal tipping fees. Tipping fees can range from $20 per cubic yard to over $200 per cubic yard depending on the contaminant and concentration. If the excavated material cannot be landfilled, disposal costs can rise dramatically. In addition, an excavation option is generally not suited for saturated soils. A recent comparison of chemical oxidation options reported average costs of over $90 per cubic yard (Ground Water Monitoring & Remediation 30, no 4/Fall 2010). The installation costs of mechanical systems (soil vapor extraction, dual phase extraction, groundwater treatment, etc.) are highly variable and dependent on the size of the treatment area but can easily exceed $20 per cubic yard even for large projects with operation and maintenance adding additional costs. Aerobic bioremediation projects are generally in the $10 to $30 per cubic yard range for a single injection and anaerobic bioremediation projects are generally in the $2 to $6 per cubic yard range for a single injection. Although multiple injections can be required, most sites require less than 3 or 4 injections if the site is properly assessed.
Minimal O&M: Bioremediation of a subsurface contaminant is typically accomplished by enhancing natural processes. These enhancements usually include the addition of a material into the subsurface and then allowing naturally-occurring microbes to degrade the constituents of concern. Because this is essentially an apply-and-forget type of technology, there are little or no operating or maintenance costs after the material has been applied. Normal monitoring is usually required on quarterly or semi-annual basis to evaluate the progress of the application.
No above ground surface structures: Injection of material into the subsurface can generally be accomplished through the use of direct injection or through permanent injection points. If the application is done through direct injection, minimal disturbance of the surface is required during the injection event and the area can be put back into use immediately after the injection is completed. Injection through permanent points can require the installation of surface and near-surface utilities and some above-grade structures but these can usually be minimized through the use of technologies such as horizontal drilling to reduce impact to facility operations.
PERFORMANCE
Remedial technologies can be divided into two basic categories, contaminant removal or contaminant destruction. To meet complete removal or destruction, both approaches require the practitioner to continue remediation until all of the contamination has been addressed. The main cause of remedial option failure is the inability of a strategy to address sufficient contamination within a system to meet the goals of a project. Biological degradation relies upon natural processes that under ideal conditions can be capable of complete degradation of a contaminant. Ideal conditions are seldom, if ever, encountered in the field therefore the goals of bioremediation need to be commensurate with the resources available.
Complete mineralization: Mineralization, or conversion of an organic to carbon dioxide and water, can be accomplished with bioremediation. Rates of mineralization can vary from compound to compound but a significant increase in degradation kinetics can be expected for most sites.
Mass reduction: In situations with significant contamination over large areas, bioremediation can be very effective in reducing the overall mass of contaminants. It is not unusual to see contaminant concentrations in groundwater to be reduced by at least on order of magnitude after bioremediation implementation. In general, the maximum degradation level achievable is related to the resources allocated to the project. In this respect it is extremely important to understand the goals of the project before beginning design activities.
Wide range of contaminants: Bioremediation can be effective across a very wide range of organic and inorganic contaminants. Aerobic processes can be very effective on petroleum products including benzene, toluene, ethylbenzene, and xylenes, some chlorinated compounds, and some metals such as iron. Anaerobic bioremedial processes such as halorespiration are effective on a wide range of chlorinated contaminants including chlorinated ethenes and ethanes while the addition of sulfates can be effective in providing electron acceptors for the degradation of many petroleum hydrocarbons. In the process of enhancing anaerobic bioremediation through the addition of carbon to a system many microbes will reduce the concentration of electron acceptors such as nitrates and sulfates. If these electron acceptors are identified as contaminants, the process of adding carbon to a system can also be considered an effective remedy for these constituents of concern.
DNAPL source treatment: Contaminants can be found in a number of phases within a system including dissolved, sorbed, free-phase, and as a vapor. For contaminants that are more dense than water, the free-phase can be present in a significant mass, especially in the source area near the original release. The term dense, non-aqueous-phase liquid (DNAPL) is given to this type of contaminant mass. Although most biological processes require the contaminant to be in the dissolved phase to be metabolized, the remediation of DNAPL sites has been observed to be accelerated through the addition of a carbon substrate. The mechanisms associated with this accelerated DNAPL degradation process include increased dissolution of the DNAPL due to the establishment of a chemical gradient, the increased dissolution of the DNAPL due to the release of surfactants by the microbial communities, and the increase in dissolution due to the solubility characteristics of the substrate.
FLEXIBILITY
Bioremediation can be very effective as a stand-alone strategy but when the goals of a project require remedial time frames that cannot readily be met with bioremediation or in cases where other strategies are more cost-effective, bioremediation can be used in conjunction with other technologies.
Use after chemical oxidation: Chemical oxidation is dependent upon bringing the contaminant and the chemical oxidant into contact with each other before the oxidant is expended. This usually takes place within a relatively short period of time and requires sufficient oxidant to permeate throughout the entire treatment zone. Since this is a time-sensitive process, chemical oxidation is usually best suited to compact, very permeable areas of high contaminant concentration such as source areas. In cases where chemical oxidation is applied, bioremediation can be used as a follow-on technology. Chemical oxidation of petroleum hydrocarbons can be quickly be followed by the introduction of oxygen through mechanical means (soil vapor extraction, sparging, etc.) or solid peroxygens or other electron acceptors. The addition of a carbon substrate to enhance reductive dechlorination can be effective following chemical oxidation if the addition of the substrate is delayed to allow all of the oxidant to react. This can be a very effective means of addressing both high concentrations in small areas followed by the remediation of any remaining contaminant through biological means.
Remediation of groundwater: Although co-metabolic processes usually take place outside of the cell, generally contaminants must be in the dissolved phase in order for them to be metabolized within the cells. Strictly speaking this limits the contaminants to the dissolved phase but the overall process includes both biological and physical actions. Physically, if you only destroy contaminants in the dissolved phase you will establish a chemical gradient that will continually replace the dissolved phase contaminant with contaminant from other phases until the entire system has come to a complete equilibrium (ie. all contaminant destroyed). This is one of the principles of bioremediation of DNAPL sources.
Remediation of DNAPL sources: Anaerobic bioremediation of DNAPL sources can be accomplished successfully by adding organic substrate to enhance reductive dechlorination. The main mechanisms identified that contribute to DNAPL dissolution include increased biological activity promoting increased chemical diffusion, increased solubility of contaminant daughter products leading to an overall increase in contaminant solubility, increased contaminant solubility within specific substrates, and the biological production of surfactants. This process is the basis of US Patent 20040157317, published August 2004 and assigned in part to JRW Bioremediation, L.L.C.
Remediation of unsaturated zone: In many cases, especially with regards to aerobically degradable contaminants, it is possible to biologically degrade the contaminant in the unsaturated zone. This process requires some moisture and the addition of a source of electron acceptors. Most soils contain sufficient moisture to allow the biological process to function so the critical issue becomes the distribution of the electron acceptor. Electron acceptors such as oxygen can be readily distributed throughout the system through mechanical means such as soil vapor extraction or air sparging. In these cases, the mechanism removes contaminants both biologically and through volatilization. The remediation of anaerobically degradable contaminants such as chlorinated solvents is theoretically possible under anaerobic conditions. In these cases, thorough substrate distribution is critical and is usually only achievable in high moisture soils such as clays. The soil moisture provides both connectivity for the substrate to diffuse throughout the system and water to sustain the microbial populations and provide contaminant and substrate transport.
The information on this website is presented by JRW Bioremediation, LLC for your consideration in the belief that it is reliable and accurate, however, no representation or warranty either expressed or implied is made as to the truth, accuracy, reliability, completeness or currentness of the data, information or opinions contained herein, or as to their suitability for any purpose, condition or application. Nothing contained herein shall be construed as a recommendation to use JRW Bioremediation, LLC products in conflict with restrictions set forth in existing governmental and/or other regulations or in patents. JRW BIOREMEDIATION, LLC, ITS LICENSORS, AND ITS SUPPLIERS, TO THE FULLEST EXTENT PERMITTED BY LAW, DISCLAIM ALL WARRANTIES, EITHER EXPRESSED OR IMPLIED, STATUTORY OR OTHERWISE, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, NON-INFRINGEMENT OF THIRD PARTIES' RIGHTS, AND FITNESS FOR PARTICULAR PURPOSE. JRW Bioremediation, LLC warrants its products only to the extent set forth in an executed sales agreement of purchase order by and between JRW Bioremediation, LLC and its customers and nothing contained in this information shall be construed to provide any warranties in addition to the warranties set forth in such sales agreement or purchase order.
JRW provides information regarding our products as a service to our clients. JRW is not a consultant and does not provide professional services. Every site is unique and care must be excercised by the practitioner to fully understand their own circumstances.
BIOREMEDIATION FUNDAMENTALS
In the simplest form, bioremediation is the breakdown of contaminants through biological means, typically some type of metabolism. The biological process of metabolism is based on a transfer of electrons from one substance to another resulting in a net gain in usable energy for the organism. This transfer of electrons requires a "donor" material that is commonly referred to as "food" and an "acceptor" material. In higher organisms, the last, or terminal electron acceptor is oxygen. In typical natural uncontaminated systems, food is limited which causes a competition among indigenous microbial populations for the available food, or electron donors. When an organic electron donor is released to the environment, the system becomes unbalanced and there the microbes compete for any available electron acceptors. Bringing the system back into balance is the basic concept behind enhanced bioremediation.
Most common organics like petroleum products readily act as electron donors and quickly degrade if an adequate supply of electron acceptors is present or introducted into the system. Other organics like chlorinated solvents are poor electron donors but degrade very quickly under anaerobic conditions as electron acceptors. The first step in a successful project is to determine your project goals. The second step is to determine if your contaminant will degrade faster aerobically or anaerobically. One good resource to determine degradation rates is the Handbook of Environmental Degradation Rates (Philip H. Howard et. al., 1991, CRC Press LLC). The third step is to determine the mass of contaminants and other interfering sinks such as other organics or competing electron acceptors.
Aerobic Bioremediation:
In cases where the contaminant preferentially degrades faster aerobically, enhancing bioremediation can be easily accomplished by adding an electron acceptor. There are a number of electron acceptors but oxygen is usually the most efficient. Other electron acceptors include nitrate, iron, and sulfate. Typically the form of electron acceptor is not critical as long as sufficient material can be added to meet the goals of the project. As an example, oxygen can be added mechanically through air sparging, soil vapor extraction, or tilling or chemically though the addition of dilute hydrogen peroxide or solid peroxygens. In all cases the ability to cost-effectively provide sufficient electron acceptor adequately distributed through the system is critical to successfully meeting the goals of the project.
Anaerobic Bioremediation:
Many chlorinated solvents degrade faster as electron acceptors. In these cases, an electron donor is added to the system to begin the process. As the substrate is metabolized under anaerobic conditions, an electron is released and is then used to replace a chlorine atom on the chlorinated solvent in a process known as reductive dechlorination or halorespiration.
The information on this website is presented by JRW Bioremediation, LLC for your consideration in the belief that it is reliable and accurate, however, no representation or warranty either expressed or implied is made as to the truth, accuracy, reliability, completeness or currentness of the data, information or opinions contained herein, or as to their suitability for any purpose, condition or application. Nothing contained herein shall be construed as a recommendation to use JRW Bioremediation, LLC products in conflict with restrictions set forth in existing governmental and/or other regulations or in patents. JRW BIOREMEDIATION, LLC, ITS LICENSORS, AND ITS SUPPLIERS, TO THE FULLEST EXTENT PERMITTED BY LAW, DISCLAIM ALL WARRANTIES, EITHER EXPRESSED OR IMPLIED, STATUTORY OR OTHERWISE, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, NON-INFRINGEMENT OF THIRD PARTIES' RIGHTS, AND FITNESS FOR PARTICULAR PURPOSE. JRW Bioremediation, LLC warrants its products only to the extent set forth in an executed sales agreement of purchase order by and between JRW Bioremediation, LLC and its customers and nothing contained in this information shall be construed to provide any warranties in addition to the warranties set forth in such sales agreement or purchase order.
Chlorinated Solvents
Metals
The practice of adding a carbon substrate to the subsurface is an attempt to bring into balance electron donors and electron acceptors within a system. Since the carbon substrate acts as an electron donor, any electron acceptor identified as a “contaminant” can usually be treated with this method.
As an example, if oxygen were considered a contaminant at a site, adding a carbon source would provide the indigenous microbial populations an electron donor which can be metabolized using the oxygen as an electron acceptor. The same can be said for any materials or “contaminants” that can be used as an electron acceptor.
This leaves open a wide range of materials that can theoretically be metabolized, and therefore “remediated” by adding a carbon substrate to a system. To move down the oxidation-reduction potential (ORP) “ladder”, the most common electron acceptors are oxygen, nitrate, iron, manganese, and sulfate.
CHLORINATED SOLVENTS
The metabolism of chlorinated solvents, most notably the chloroethenes, chloroethanes, and the chloroebenzenes degrade through the process of halorspiration or reductive dechlorination with the substrate being fermented to produce hydrogen. Halorespiration can also be an important mechanism for contaminants such as chlorinated pesticides and herbicides.
METALS
The process of biologically treating metals uses the differences in solubilities of each metal under various oxidative states. Iron is typically insoluble under aerobic conditions but becomes soluble under reducing conditions. A system can be further driven anaerobic producing sulfides that can react with the metals forming insoluble or less soluble metal sulfides.
The following is a short list of contaminants that can be bioremediated through the introduction of a carbon substrate:
Perchloroethene;
Trichloroethene;
Dichlorethene;
Vinyl Chloride;
1,1,1-Trichlorethane;
1,2-Dichloroethane;
Carbon tetrachloride;
Chloroform;
Chlorobenzenes;
Chlorinated pesticides (e.g., chlordane), polychlorinated biphenyls (PCBs), and chlorinated cyclic hydrocarbons (e.g., pentachlorophenol);
oxidizers such as perchlorate and chlorate;
explosive and ordnance compounds;
dissolved metals (e.g., hexavalent chromium); and
nitrate and sulfate*.
*Principles and Practices of Enhanced Anaerobic Bioremediation of Chlorinated Solvents, Air Force Center for Environmental Excellence, Brooks City-Base, Texas and Naval Facilities Engineering Service Center, Port Hueneme, California, August 2004, AFCEE, Contract F41624-00-D-8024 and NFESC, Contract N47408-98-D-7527.
Information on the potential to degrade various materials either aerobically or anaerobically through biological means can be found in the Handbook of Environmental Degradation Rates (Phillip Howard, et. al., Heather Taub Printup Editor, Lewis Publishers, 1991).
JRW provides information regarding our products as a service to our clients. JRW is not a consultant and does not provide professional services. Every site is unique and care must be excercised by the practitioner to fully understand their own circumstances.
The information on this website is presented by JRW Bioremediation, LLC for your consideration in the belief that it is reliable and accurate, however, no representation or warranty either expressed or implied is made as to the truth, accuracy, reliability, completeness or currentness of the data, information or opinions contained herein, or as to their suitability for any purpose, condition or application. Nothing contained herein shall be construed as a recommendation to use JRW Bioremediation, LLC products in conflict with restrictions set forth in existing governmental and/or other regulations or in patents. JRW BIOREMEDIATION, LLC, ITS LICENSORS, AND ITS SUPPLIERS, TO THE FULLEST EXTENT PERMITTED BY LAW, DISCLAIM ALL WARRANTIES, EITHER EXPRESSED OR IMPLIED, STATUTORY OR OTHERWISE, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, NON-INFRINGEMENT OF THIRD PARTIES' RIGHTS, AND FITNESS FOR PARTICULAR PURPOSE. JRW Bioremediation, LLC warrants its products only to the extent set forth in an executed sales agreement of purchase order by and between JRW Bioremediation, LLC and its customers and nothing contained in this information shall be construed to provide any warranties in addition to the warranties set forth in such sales agreement or purchase order.
ELECTRON DONORS
Highly Soluble Substrates
Slowly Soluble Substrates
Carbon substrates for enhanced reductive dechlorination can be duvided into two main categories related to their longevity in the subsurface: slowly soluble and readily soluble substrates. In reality these categories can be better defined by the dissolution rate of the substrate with readily soluble substrates being materials that are miscible or semi-miscible in groundwater and slowly soluble substrates being generally recognized as dissolving over a period of multiple months. The dissolution rate is an important characteristic as it gives a clue to how much substrate is required per period of time.
Since the addition of a substrate is intended to establish and maintain conditions supportive of robust anaerobic metabolism for a period of time sufficient to completely degrade the contaminants, it is important to understand how much substrate will be available for metabolism over any given period of time. In general, because they dissolve more slowly, less soluble substrates require higher dosing to maintain the same amount of available dissolved carbon within a system per unit time. If the goals of the project require maintaining anaerobic conditions for an extended period of time, the design should allow for multiple injections and/or the use of a slowly soluble substrate. If the project goals require maintaining anaerobic conditions for only a short period of time (on the order of months rather than a year to two), the design can include a highly soluble substrate.
Highly Soluble Substrates
The physical properties of a substrate will also impact subsurface distribution. Post-injection distribution is impacted by advective flow and to some extent chemical diffusion. Highly substrates like WILCLEAR®, WILCLEAR Plus®, and SoluLac™ can mimic water in their movement in the subsurface and are ideal for recirculation systems with limited injection points. They can also quickly diffuse in tight formations or formations with minimal groundwater flow.
WILCLEAR® sodium lactate and potassium lactate are both highly soluble substrates. Sodium lactate was one of the first substrates to be used in the field to enhance reductive dechlorination. Both are easy to use and store and are excellent substrates for recirculation systems.
Slowly Soluble Substrates
Slowly soluble substrates like LactOil® soy microemulsion and ChitoRem® chitin complex can maintain anaerobic conditions in most aquifers for over two years.
LactOil® is unique in that the microemulsion allows the diluted material to have physical properties similar to highly soluble substrates while still retaining the slow dissolution properties of a vegetable oil. This combination provides the best characteristics of both highly soluble substrates (superior dispersion characteristics) and vegetable oils (longevity).
ChitoRem® chitin complex is a solid matrix that contains protein, chitin, and calcium carbonate. The protein provides an immediately available carbon source, the chitin provides a slow release carbon source and trace nitrogen for improved microbial growth, and the calcium carbonate provides a buffering agent. This material is ideal as an excavation or as a high-pressure fracturing substrate. ChitoRem® is also being developed as a bioreactor substrate for acid mine drainage (mine influenced water).
JRW provides information regarding our products as a service to our clients. JRW is not a consultant and does not provide professional services. Every site is unique and care must be excercised by the practitioner to fully understand their own circumstances.
CONTACT JRW FOR ADDITIONAL INFORMATION
Nutrient Supplements
Under normal conditions there are sufficient nutrients to sustain microbial growth but when a release occurs, metabolism may be limited by the balance in electron donors and acceptors or the available nutrients. This nutrient limitation may not be apparent once a substrate has been added to a system as degradation kinetics are significantly increased. In order to maximize degradation kinetics, the addition of a nutrient is prefered. In cases where a system is partially nutrient limited and there is excess substrate, the addition of a nutrient can not only increase kinetics but also increase substrate utilization efficiency as less of the substrate is used for non-degradation growth.
There are two types of nutrients supplements, those that provide growth factors and those that provide trace metals and minerals.
JRW’s Accelerite® biormediation nutrient is a specially formulated mix of growth factors that quickly stimulates anaerobic metabolism increasing both degradation kinetics and substrate utilization efficiency. Accelerite® can be added to any substrate to increase effectiveness. Field tests have shown that Accelerite® incresed overall microbial growth by over two orders of magnitude when used with emulsified vegetable oil or ethyl lactate within 12 days and within 22 days when used with whey powder. These systems rapidly began to become anaerobic quickly reaching sulfate reducing levels while reducing PCE almost 40% in 13 days and almost 90% in 82 days.
Accelerite® has also been added to systems that showed a potential over application of substrate causing a drop in pH and very high TOC. Within 30 days of application, TCE began dropped from over 3 mg/L to less than 50 ug/L and the pH began to rise. After 90 days, and the TCE dropped to non-detectable levels and DCE dropped from over 13 mg/L to under 3 mg/L while VC dropped from over 23 mg/L to less than 5 mg/L.
JRW’s ChitoRem® chitin complex contains about 1% nitrogen in a slow-release form that can help stimulate microbial growth. This can be important in poor soils or in situations where very high biomass is desired such as biochemical reactors.
CONTACT JRW FOR ADDITIONAL INFORMATION
PRODUCT SELECTION
Readily Soluble Substrates
Slowly Soluble Substrates
Readily Soluble Substrates:
The selection of a specific substrate should take into consideration a number of factors such as the goals of the project, hydrogeology, comtaminant profile, geochemistry, plume characteristics, and remedial resources. As part of the available resources, the experience of the practioner as well as the injection crew need to be taken into account as injection of slurried solids like ChitoRem® under pressure in a low permeability soil can be significantly different than the injection of a miscible liquid like WILCLEAR® into a sandy matrix. Materials handling also can play a role in substrate selection as some substrates promote growth so vigorously that they need to be injected within a few days after being diluted to prevent biomass from growing in the mix tanks, while others have special storage requirements.
Readily Soluble Substrates:
Substrates such as JRW’s WILCLEAR®, WILCLEAR Plus®, SoluLac®, and LactOil® are very soluble in water. These materials readily mix reducing substrate preparation costs and move well through groundwater advection. This characteristic can be beneficial when designing a system to manage groundwater flow through recirculation systems or groundwater pump and treatment systems. Readily soluble substrates are also of significant value when multiple injections are planned. This can be done through either injection or through permanent injection points.
LactOil® soy microemulsion is a unique substrate that combines the solubility characteristics of highly soluble materials like lactates with the dissolution properties of vegetable oil. This allows the material to be injected like a readilty soluble substrate for superior distribution in situations where a slowly soluble substrate is desired.
Slowly Soluble Substrates:
Substrates such as JRW’s LactOil® and ChitoRem® are slowly soluble in water but at the same time provide carbon for extended periods depending on advective velocity and microbial activity. LactOil® is a soy microemulsion that provides carbon for at least as long as standard vegetable oil emulsions. LactOil® contains ethyl lacate as part of the microemulsion to slowly provide highly efficient lactate to the aquifer over extended periods of time.
ChitoRem® is a solid complex containing chitin, calcium carbonate, and protein. The chitin acts as a slow release substrate while the protein drives an aquifer anaerobic very quickly. Both also contain the essential nutrient nitogen to rapidly promote and maintain microbial growth. The calcium carbonate is in a form that slowly releases into the system without armouring to provide a long-term buffering agent.
The selection of a substrate is site and project specific and should be conducted with the goals of the project in mind. Contact JRW for suggested uses based on your site-specific needs.
CONTACT JRW FOR ADDITIONAL INFORMATION
BIOAUGMENTATION
The question of bioaugmentation, or the addition of one or more species of microbe into a system has been debated since the late 1990’s. AFCEE’s Principles and Practices of Enhanced Anaerobic Bioremediation of Chlorinated Solvents (AFCEE 2004, page 2-17) states that “In practice, microorganisms capable of degrading PCE and TCE to cis-DCE should be considered ubiquitous in the subsurface environment.” This would suggest that degrading down to cis-DCE is pretty much just a balance of electron donors and acceptors for almost all sites. And since cis-DCE can degrade through a number of both aerobic and anaerobic pathways, for most sites, the issue of adding microbes becomes one of economics rather than of risk. The AFCEE guidance document also discusses evidence that mixtures of microbes capable of complete degradation of PCE to ethene in the absence of Dehalococcoides suggests that specific microbial strains are not necessarily required to achieve complete dechlorination. Site work over the years has bolstered this idea.
But bioaugmentation can play an important role in a remedial approach. Although the indigenous dechlorinating populations may arguably be the most acclimated to a specific site, geochemical conditions may inhibit optimal growth such that sufficient numbers of microbes may not be available to support robust dechlorination. At other times, sufficient quantities of dechlorinating microbes capable of quickly promoting complete dechlorination to ethene may not be present. In these cases, bioaugmentation can be an valuable tool.
JRW provides information regarding our products as a service to our clients. JRW is not a consultant and does not provide professional services. Every site is unique and care must be excercised by the practitioner to fully understand their own circumstances.
CONTACT JRW FOR ADDITIONAL INFORMATION
SUBSTRATE DELIVERY
Injection Through Permanent Wells
Direct Push Injection
Soil Mixing
One of the most important design considerations is the dispersal of the substrate in the subsurface. If you cannot obtain and maintain control of the system (aquifer), you cannot consistently manage the microbial processes reponsible for reductive dechlorination. This is directly related to the selection of a substrate delivery method. In most cases, there are three methods of delivering a substrate: injection through existing wells or injection galleries, injection through direct push equipment, and direct mixing with soil. The physical properties of the substrate can also directly affect the delivery method.
Injection Through Permanent Wells
One popular substrate delivery method is injection through permanent wells. Permanent wells have the advantage of being readily available for additional applications. The disadvantages of permanent wells is their capital cost, limited coverage, their susceptability to damage, and their limited use with solid or very viscous substrates. Since most plumes require multiple injections, permanent wells have become popular. This limits the number of times that a drilling crew must be mobilized and provides some level of flexibility with regards to reinjection timing. Permanent wells are best suited to long-term systems such as recirculation systems or barriers and are less suited to very large plumes where control of the aquifer is impractical. Highly viscous substrates can significantly complicate injection through permanent wells and the injection of solid substrates may not be possible. Also, the capital costs of permanent wells may not be financially justifiable on sites that do not have groundwater recirculation or control systems and require only one or two injection events.
Direct Push Injection
Direct push injection of substrates allows the practitioner to optimize injection point placement but the direct push process is limited to the depth capability of the available equipment. Generally speaking, light to moderate weight direct push equipment is limited to less than about 75’ below ground surface in most situations. Deeper injections have been accomplished but these are not the norm. The advantages of direct push injection are the short site time and cost. Generally, direct push points can be completed in an hour or so each, thereby increasing the amount of plume that can be covered in a given time period. Direct push injection can also be very valuable at sites requiring fracturing of the soils. With soild substrates like ChitoRem® this can be done by suspending the substrate in a slurry of guar and water. The resulting mixture can be injected with standard direct push tools or with specialized hydraulic fracturing equipment for deep applications.
Soil Mixing
Substrates can also be mixed with the soils at the bottom of an excavation or at the surface. This is usually done with solid substrates but can also be done with liquid substrates. The technique is limited in that it can only impact the soil and groundwater in the immediate vicinity of the substrate, and any water flowing through the substrate but this is the most inexpensive application method. Generally, the substrate is spread across the surface and then “raked’ into the top few inches of exposed soil. The ”raking” can be done with the teeth of a bucket on an excavator or even by hand. In theory, any water that flows through the treated area picks up carbon and moves that carbon into the same groundwater zones responsible for contaminant travel. This technique can be an excellent addition to injections.
JRW provides information regarding our products as a service to our clients. JRW is not a consultant and does not provide professional services. Every site is unique and care must be exercised by the practitioner to fully understand their own circumstances.
CONTACT JRW FOR ADDITIONAL INFORMATION
FAQs
Q. How much will it cost to remediate my site?
A. Enhanced reductive dechlorination is based on attaining and maintaining control of an aquifer for a period of time sufficient to degrade all constituents of concern and their daughter products. Attaining and maintaining control of an aquifer is highly dependent on the hydrogeology and geochemistry of the site along with the microbial populations present. Since the hydrogeology and geochemistry is different for every site, a blanket cost can not be given for any specific site. In general, enhanced reductive dechlorination will cost less than $10 per cubic yard of media treated on most non-DNAPL sites. This compares with about $60 per cubic yard for excavation (without disposal) and about $90 per cubic yard for chemical oxidation.
Q. Can I reach MCLs with enhanced reductive dechlorination?
A. In some cases, MCLs can be attained with enhanced reductive dechlorination. Much more frequently, reductions in contaminant mass of one to two orders of magnitude are common.
Q. Do the costs include freight?
A. Because freight is costed from a warehouse to a delivery point, freight costs are quoted separately. Unless otherwise stated, due to the volatility of the fuels market, freight costs are generally valid for 30 days. Consideration should be given to the receiving facility’s capacity to off load a truck. In situations where the product is delivered to a facility without the capacity to off-load a delivery vehicle, arrangements can be made (for an additional charge) for delivery on a vehicle with a lift gate and pallet jack.
Q. When do I need to reinject?
A. Reinjection schedules should be based on the geochemistry of an aquifer and not on a calendar schedule. In many cases, multiple injections can be spaced further apart over time.
Q. Will reductive dechlorination work in tight clay?
A. Since the main goal of adding a substrate to an aquifer is to attain and maintain anaerobic conditions for an extended period of time, because of the limited flows clay sites should be ideal for enhanced reductive dechlorination. In practice, clay sites with adequately spaced injection points usually show very rapid response to substrate addition.
Q. What should my injection spacing be?
A. Injection spacing should be sufficient to promote robust reductive dechlorination throughout the treatment zone for a time sufficient to attain complete reductive dechlorination. Injection spacing is dependent upon the dissolution rate of the substrate, the dosage, aquifer velocity, and competing electron acceptor and contaminant flux.
CONTACT JRW FOR ADDITIONAL INFORMATION
Products Overview
• 61% fermentable blend containing lactate and other fermentable materials and water soluble nutrients including B-vitamins and yeast factors.
• Designed for rapid dechlorination of chlorinated aliphatic hydrocarbons and reduction of certain metals and sites where sluggish microbial activity may be hindering dechlorination.
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• 80% fermentable blend containing both quick release ethyl lactate and slow release long-chain oleaginous materials.
• Designed for sites where a slow release substrate is needed (i.e. sites with high mobilization/injection costs), DNAPL source treatment, PRBs, cutoff walls.
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• Proprietary nutrient blend of yeast metabolites including B-vitamins and other soluble nutrients.
• Designed to be used with any carbon substrate to enhance microbial growth and activity and improve donor efficiency and kinetics.
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• Solid material that provides both a readily soluble carbon substrate as well as a slow release carbon source.
• Perfect for open excavations, direct push applications, acid mine drainage and low alkalinity halogenated solvent sites.
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• A readily soluble food grade 60% sodium or potassium lactate solution.
• Great for sites where rapidly established anaerobic conditions are needed, nitrate reduction, and perchlorate degradation.
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• 99.8% fermentable material.
• Excellent for dissolution of sorbed solvents and/or DNAPL.
Conferences
2011
JRW will be participating in the following conferences:
May 16-19 – REMTEC, Chicago, IL (Exhibiting)
June 1-3 – AEHS International Conference on Green
Remediation, Amherst, MA (Exhibiting)
June 11-16 – American Society of Mine Reclamation,
Bismarck, ND (Exhibiting)
June 27-30 – Battelle Symposium on Bioremediation and
Sustainable Environmental Technologies,
Reno, NV (Exhibiting)
Corporate Office:
JRW Bioremediation, L.L.C.
14321 W. 96th Terrace
Lenexa, Kansas 66215
Phone:
(800) 779-5545
Fax:
(913) 438-5554
Email:
custserv@jrwbiorem.com
Ordering/Samp
To place an order contact:
JRW Bioremediation, L.L.C.
14321 W. 96th Terrace
Lenexa, KS 66215
Phone:
(800) 779-5545
FAX:
(913) 438-5554
Please allow sufficient time for processing and transportation. For most situations a lead time of at least 3 weeks will ensure on-time delivery.
SAMPLES:
Samples of JRW products are available on a limited basis for research work. Contact JRW at the number above to request a sample or discuss potential application strategies.
News
November 2010, Saint Louis, MO
JRW receives ITRC’s Industy Recognition Award – Mike Sieczkowski was presented with the Mining Waste Team’s Industry Recognition Award for 2010 at the ITRC Fall Meeting held in Saint Louis, MO. Mike has been active as a contributing author for both the Mining Waste Team and the Integrated DNAPL Site Strategy Team for the past four years. JRW is pleased to be a member of ITRC’s Industrial Affiliates Program and has been a strong supporter of ITRC and its programs. In 2011, Mike will be JRW’s representative on both the Itegrated DNAPL Site Strategy Team as well as the new Biochemical Reactors for Mining-Influenced Water Team.
JRW Bioremediation, L.L.C.
14321 W. 96th Terrace, Lenexa, Kansas 66215
(913) 438-5544
