Bioremediation

Bioremediation is the use of biological systems, usually microorganisms, to treat polluted soils and water. Optimization of bioremediation processes generally requires the addition of inorganic materials (biostimulation), such as utilizable sources of nitrogen, phosphorus, and oxygen. Generally, appropriate microorganisms are present in the polluted material and do not have to be added. However, occasionally natural or genetically engineered microbes may need to be added (bioaugmentation). Treatments can be either ex situ or in situ. The technology can involve aerobic and/or anaerobic bioreactors, biofiltration, air sparging, bioventing, composting, landfarming, and biopiles. Intrinsic remediation refers to the combined effects of all natural processes in contaminated environments that reduce the mobility, mass, and risks of pollutants. The limitations of bioremediation are discussed, including the treatment of petroleum pollution in the sea.