Bioremediation can be defined as any process that uses microorganisms or their enzymes to return the environment altered by contaminants to its original condition. Bioremediation can be employed to target specific contaminants, such as chlorinated pesticides that are degraded by bacteria, or a more general approach can be taken, such as oil spills that are analyzed with multiple techniques, including the addition of fertilizers to facilitate the decomposition of crude oil by bacteria.
Not all contaminants are easily treated by using bioremediation, for example, heavy metals such as cadmium and lead are not easily absorbed or captured by organisms. Integrating metals like mercury into the food chain can make things worse as organisms accumulate these metals.
However, there are a number of advantages to bioremediation, which can be used in areas that cannot be easily reached without the need for excavation. For example, oil spills (gasoline or petroleum) can contaminate groundwater far below the earth's surface, injection of law enforcement agencies, in connection with the formation of oxygen compounds, can significantly reduce concentrations after a period of time. This is much less expensive than excavating other burial or incineration sites, and reduces or eliminates the need for pumping and treatment, which is common practice at sites where hydrocarbons have contaminated groundwater.
In general, bioremediation technologies can be classified as in situ or ex situ. In situ bioremediation consists of treating contaminated material on site, while ex situ is the removal of contaminated material to be treated elsewhere. Examples of bioremediation technologies are bioventilation, farmland, bioreactors, composting, biostimulation and bioaugmentation.
Authors: Val
