Contaminants
What is bioremediation used for? Bioremediation is the use of microbes to clean up contaminated soil and groundwater. Microbes are very small organisms, such as bacteria, that live naturally in the environment.
Application Corner
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 microemulsion, and ChitoRem® chitin complex.
JRW Bioremediation, LLC and COVID-19
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.
1. Fundamentals
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.
2. 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.
3. Metals
The process of biologically treating metals uses the differences in solubility 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.
3.1 List of contaminants:
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;
- substrate: 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*.
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 exercised by the practitioner to fully understand their own circumstances.