What Is Bioremediation?

Bioremediation is a branch of biotechnology employing the use of living organisms like microbes and bacteria to remove contaminants, pollutants, and toxins from soil and water. Bioremediation may be used to clean up environmental problems such as oil spills, or contaminated groundwater.

Key Takeaways

  • Bioremediation is a biotechnological discipline where microbes, bacteria, and other living organisms remove contaminants from soil and water. 
  • Bioremediation is traditionally used to clean oil spills or contaminated groundwater.
  • Bioremediation may be done "in situ," at the site of the contamination, or "ex situ," away from the site. 

How Bioremediation Works

Bioremediation relies on stimulating the growth of certain microbes that utilize contaminants like oil, solvents, and pesticides for sources of food and energy. These microbes convert contaminants into small amounts of water, as well as harmless gases like carbon dioxide.

Bioremediation requires a combination of the right temperature, nutrients, and foods. The absence of these elements may prolong the cleanup of contaminants. Conditions that are unfavorable for bioremediation may be improved by adding “amendments” to the environment, such as molasses, vegetable oil, or simple air. These amendments optimize conditions for microbes to flourish, thereby accelerating the completion of the bioremediation process.

Bioremediation can either be done "in situ", which is at the site of the contamination itself, or "ex situ," which is a location away from the site. Ex situ bioremediation may be necessary if the climate is too cold to sustain microbe activity, or if the soil is too dense for nutrients to distribute evenly. Ex situ bioremediation may require excavating and cleaning the soil above ground, which may add significant costs to the process.

The bioremediation process may take anywhere from several months to several years to complete, depending on variables such as the size of the contaminated area, the concentration of contaminants, temperature, soil density, and whether bioremediation will occur in situ or ex situ.

Advantages of Bioremediation

Bioremediation offers numerous advantages over other cleanup methods. By relying solely on natural processes, it's a relatively green method that minimizes damage to ecosystems. Bioremediation often takes place underground, where amendments and microbes can be pumped, in order to clean up contaminants in groundwater and soil. Consequently, bioremediation does not disrupt nearby communities as much as other cleanup methodologies.

The bioremediation process creates relatively few harmful byproducts, mainly due to the fact that contaminants and pollutants are converted into water and harmless gases like carbon dioxide. Finally, bioremediation is cheaper than most cleanup methods, as it does not require substantial equipment or labor. By the end of 2018, the United States Environmental Protection Agency historically brought bioremediation activities to a total of 1,507 sites.