WHAT IS MICROBE BIOREMEDIATION?

by Richard W. Popino, Ph.D. REM

Bioremediation is a remediation technology that uses bacteria or other micro-organisms to clean up contamination. The bacteria breaks down the contamination into less harmful components, such as carbon dioxide and water. Microbe bioremediation can be used to clean up soil or water. Water and nutrients may be added to the contaminated soils to speed up the breakdown process. The contamination can be treated in place (in situ) or the material excavated and treated above ground in a different location (ex situ).

With most bioremediation projects, microorganisms are utilized and managed through the control of environmental factors to reduce environmental pollution.  Most cleanups utilize indigenous microorganisms, although some rely on the introduction of additional bacterial or fungal strains.  Studies are currently being performed on genetically engineered microbes. The bacteria feed on the contamination, deriving nutrition for growth and reproduction.  Undergoing complex chemical reactions, the waste is metabolized into the final metabolic products, usually water and carbon dioxide.  This provides the bacteria with the energy they need to live.

A bacterium is a single cell organism. Bacteria often grow in colonies but each cell remains an independent life. Bacteria reproduce by "cell division".  A mature bacterium reproduces by dividing into two "daughter cells," each cell identical to the other and the parent bacteria.  Under ideal conditions, bacteria can reproduce rapidly, producing a new generation every 20 to 30 minutes. Thousands of different species of bacteria exist and most carry on bacterial digestion in some way.  However, some are found only in a specific environment, require specialized food, or maintain unique niches.  Eventually the food source will be depleted, or some other change in the environment will cause the population to decrease.  These changes may be pH, temperature, or oxygen content.

The objective of a microbe bioremediation project is to immobilize or transform them to chemical products no longer hazardous to human health and the environment. For certain cases in which contaminants pose no significant risk to sensitive receptors (e.g., water supply wells, surface water bodies), intrinsic bioremediation may be an appropriate strategy. For other cases in which receptors are at risk, an engineered bioremediation strategy may be necessary.  Engineered bioremediation can be performed in-situ (e.g., biosparging; bioventing, hydrogen peroxide/inorganic nutrient amendment) or ex-situ (e.g., land farming, biopiles), depending on a variety of site-specific factors and the constraints imposed by site usage. In many instances, biostimulation activities may be limited to electron acceptor (e.g., molecular oxygen, nitrate, etc.) amendment, however, in other cases inorganic nutrient amendment or pH adjustment may be required.
Microbe Bioremediation has demonstrated that it is an important remediation technology because it:

·  Uses naturally-occurring biochemical processes;

·  Destroys or immobilizes contaminants; and

·  Takes less time and costs a great deal less than conventional cleanup technologies.

In many cases, contaminants such as petroleum hydrocarbons serve as sources of organic carbon and electron donors (assimilation). In other metabolic processes, contaminants such as trichloroethylene may serve as electron acceptors (reductive dehalogenation), or may be transformed by processes that offer no added benefit to microbes from the reactions (co-oxidation). These processes occur within a wide range of hydrogeologic settings, biogeochemical interactions, microorganisms, and contaminants.

During implementation of a microbe bioremediation project monitoring plays a key role in evaluating treatment effectiveness.  Microbe biodegradation monitoring objectives are generally to evaluate contaminant attenuation over time and protect sensitive receptors.  Properly executed, microbe bioremediation can cost-effectively and expeditiously destroy or immobilize contaminants in a manner that fosters regulatory compliance and is protective of human health and the environment.

The technology has consistently demonstrated that it can substantially reduce toluene, benzene, ammonia, nitrogen, lead, arsenic, mercury, acidity, and even PCBs.  Consequently, Common Sense Solutions, LLC presents this alternative to parties considering more expensive and less effective methods.  We target five distinct industries and assist vendors with signing contracts with the largest corporate polluters for their multiple and "mega" sites. 

Common Sense Solutions, LLC has been working with hazardous waste and petroleum sites for 27 years and, as a result, has acquired site and owner lists, as well as valuable corporate and regulator contacts.  Typically, we seek "no costä demonstration plots of contaminated soil and/or a comparable wastewater holding ponds to determine whether bioremediation is suitable.  In very little time, testing usually documents this extraordinary technology's benefit.  Demonstrations convince regulators and assure the responsible parties that they could substantially reduce cleanupâs time and cost.  Our credentials and credibility have opened doors for demonstrations and meetings that would otherwise have been difficult to arrange.

In Washington, D.C., Common Sense Solutions, LLC lobbies Congress for companies with new technologies.  We are positioned to market bioremediation products and also obtain contracts with the nation's worst polluters.  Our credibility could greatly enhance your success with "big ticket" polluters and their regulators.  

For more information call: 1-800-759-9170
or email us at: info@csshome.com.

Works Consulted

Dart and Stretton; Microbial Aspects of Pollution Control.  New York: Elsevier Scientific Publishing Company, 1977.

Gibson, D.T., and Sayler, G.S. 1992. Scientific Foundations of Bioremediation: Current Status and Future Needs. American Academy of Microbiology, Washington, D.C., USA

Jorgensen, B.B. 1989. Biochemistry of Chemoautotrophic Bacteria. In Schlegel, H.G. and Bowien, B. (editors), Autotrophic Bacteria, Science Technology Publishers, Madison, Wisconsin, USA, p. 117-146

Norris, Robert D.; Fourth Quarter 1996 Practical Applications of Bioremediation Technology.  Remediation Management.

Rosenberg, E.; Microorganisms to Combat Pollution;  Boston: Kluwer Academic Publishers, 1993. 

Schaffner, Richard, Bioremediation Discussion Group, Bioremediation: A Single-Celled Solution for Mitigating Environmental Contamination; The BioGroup includes over 2,400 members worldwide, including environmental consultants, industry representatives, regulators, researchers, educators, students, and others with diverse backgrounds in education and experience.  

Sutherson, Suthan S. Remediation Engineering; Design Concepts.  New York: CRC Lewis Publishers, 1997.