Bioremediation: Using Living Organisms to Clean the Environment
Bioremediation is the use of living organisms for the recovery or cleaning up of a contaminated medium such as soil, sediment, air, or water. "Remediate" means to solve a problem and "bioremediate" means to use biological organisms to solve an environmental problem such as contaminated soil or groundwater.
The process of bioremediation might involve the introduction of new organisms to a site or the adjustment of environmental conditions to enhance degradation rates of indigenous fauna.
Why It Is Used
Bioremediation can be applied to recover brownfields for development and for preparing contaminated industrial effluents prior to discharge into waterways. Bioremediation technologies also are applied to contaminated wastewater, ground or surface waters, soils, sediments, and air where there has been either accidental or intentional release of pollutants or chemicals that pose a risk to human, animal, or ecosystem health.
Different approaches to bioremediation take advantage of the metabolic processes of different organisms for degradation or sequestering and concentration of different contaminants. For example, soil bioremediation might be performed under either aerobic or anaerobic conditions, and involve the optimization of the metabolic pathways of bacteria or fungi for degradation of hydrocarbons, aromatic compounds, or chlorinated pesticides. Phytoremediation is a type of bioremediation that uses plants and often is proposed for bioaccumulation of metals, although there are many other different types of phytoremediation.
The idea of bioremediation has become increasingly popular in the 21st century. Genetically engineered microorganisms (GEMs, or GMOs) carry recombinant proteins that can hasten the breakdown process of explosives like TNT, but these remain relatively uncommon due to regulatory constraints related to their release and control. Other methods of enzyme optimization that do not include gene cloning techniques might be applied to indigenous microorganisms to enhance their pre-existing traits.
Bioremediation is most effective when performed on a small scale. The 1986 Chernobyl nuclear disaster, for example, was far too catastrophic to be positively affected by bioremediation efforts and is essentially beyond repair. A real-life example of bioremediation is adding nutrients to the soil to enhance bacterial degradation of contaminants and increase the rate of bioremediation on a brownfield site. Bioremediation was used extensively to combat the devastating effects of the Exxon Valdez oil spill in 1989 and BP’s Deepwater Horizon oil spill in 2010. In both oil spills, microorganisms were used to consume petroleum hydrocarbons and played a significant role in reducing the environmental impact.
Bioremediation provides a good cleanup strategy for some types of pollution, but it will not work for all. For example, bioremediation may not provide a feasible strategy at sites with high concentrations of chemicals that are toxic to most microorganisms. These chemicals include metals such as cadmium or lead and salts such as sodium chloride.
An Everyday Example
Bioremediation can be performed on a personal level. For example, composting is something anyone can do, and it’s a fantastic way to recycle garden and yard waste nutrients to create a soil conditioner.
Nutrients can be added to the soil to enhance bacterial degradation of contaminants and increase the rate of bioremediation on the brownfield site.