Bioremediation is the use of microorganisms for the degradation of hazardous chemicals in soil, sediments, water, or other contaminated materials. Often the microorganisms metabolize the chemicals to produce carbon dioxide or methane, water and biomass.
Our approach to substrate dosing is based on site conditions. JRW Bioremediation L.L.C. provides substrates and nutrients for anaerobic bioremediation. The substrates provided include highly soluble materials such as WILCLEAR® sodium and potassium lactate, SoluLac® ethyl lactate, and Wilke Whey® whey powder and slowly soluble substrates including LactOil® soy micro-emulsion, and ChitoRem® chitin complex.
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.
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.
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.
JRW is committed to the health and safety of our employees and our clients during the COVID-19 health crisis. Although our core business is considered essential, JRW has taken the step of encouraging all non-essential personnel to work remotely whenever possible. Our communications program seamlessly integrates telephone and web contact with each individual within the organization as well as our clients allowing staff to limit personal face to face contact while maintaining a high degree of personal attention. Each staff member has real-time access to project files and order databases allowing us to work remotely to maintain up to date information about your project and the status of your order. Our technical, logistics and administrative professionals also remain available to assist in your project planning and execution.
We will continue to work to maintain a commitment to superior service throughout the current health situation and hope that you, your staff, and their families remain healthy.
JRW is committed to the health and safety of our employees and our clients during the COVID-19 health crisis. Although our core business is considered essential, JRW has taken the step of encouraging all non-essential personnel to work remotely whenever possible.
Our communications program seamlessly integrates telephone and web contact with each individual within the organization as well as our clients allowing staff to limit personal face to face contact while maintaining a high degree of personal attention. Each staff member has real-time access to project files and order databases allowing us to work remotely to maintain up to date information about your project and the status of your order. Our technical, logistics and administrative professionals also remain available to assist in your project planning and execution.
We will continue to work to maintain a commitment to superior service throughout the current health situation and hope that you, your staff, and their families remain healthy.
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.
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.
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.
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.
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.
