How Bioremediation Works - Bioremediation Treatment Information

How does bioremediation work? The process commonly referred to as bioremediation, is a treatment process that uses microorganisms (yeast, fungi, or bacteria) to break down, or degrade, hazardous substances into less toxic or nontoxic substances. Microorganisms, just like humans, eat and digest organic substances for nutrients and energy. In chemical terms, "organic" compounds are those that contain carbon and hydrogen atoms. Certain microorganisms can digest organic substances such as fuels or solvents that are hazardous to humans. Thus, how bioremediation works is by allowing microorganisms to break down the organic contaminants into harmless products -- mainly carbon dioxide and water, commonly referred to as bioremediation.

There are two general categories of bioremediation, in site and ex site. Ex site bioremediation is the process of removing contaminated soil or water and treating it elsewhere. Ex site bioremediation is usually done with one of two methods, landfarming or in a bioreactor. In landfarming soil is removed and take to another area where it is spread out in thin layers, about 18 inches deep. Then biological materials (microbes) are added and the land is tilled to aerate. Ex site bioreactor processes involve removal of the soil or wastewater to be placed in a reactor. Once in the reactor the microbes are added and the temperature and, in the case of soil, moisture is controlled to obtain maximum degradation.

After a site is bioremediated, the microbial populations return to a level consistent with the amount of food and water available by dying off or returning to a spore state.

Bioremediation Limitations

Bioremediation is helpful in the clean up of many organic wastes, however it does have its limitations. The extent of remediation is highly dependent on the toxicity and the initial levels of contaminants, their ability to be biodegraded and the properties of the soil in which the contaminants lie. Sites that are unable to be cleaned with microbes include those with high metal concentrations (i.e. mercury), highly chlorinated organics (compounds with many chlorine elements attached), and inorganic salts. These types of compounds are toxic to the microbes.

Bioremediation is a new and promising technology in which the methods and effectiveness are continually being tested. Until this new technology improves, other forms of remediation are still needed.