Explanation:

Bioremediation is a process used to treat contaminated media, including water, soil and subsurface material, by altering environmental conditions to stimulate growth of microorganisms and degrade the target pollutants. Contaminants treated using bioremediation include oil and other petroleum products, solvents, and pesticides.
How Does It Work?
Some types of microbes eat and digest contaminants, usually changing them into small amounts of water and harmless gases like carbon dioxide and ethene.