Biodegradacion

Biodegradation

some organo-metal compounds, for example, methyl mercury and tributyltin (TBT). Because of their strong bioaccumulation and toxicity, some of these substances were banned in NorthAmerica and Western Europe after 1970. The bioconcentration factor (BCF) often serves as a trigger for the hazard classification of chemicals. In the European Union a BCF greater than one hundredleads to a substance’s classification as “dangerous to the environment.” The U.S. Environmental Protection Agency (EPA) uses a BCF of greater than 1,000 for environmentally harmful substances. In Canadachemicals with a BCF greater than 5,000 are recommended for “virtual elimination.” S E E A L S O DDT (Dichlorodiphenyl trichloroethane); Mercury; PCBs (Polychlorinated Biphenyls); PersistentBioaccumulative and T oxic (PBT) Chemicals; Persistent Organic Pollutants (POPs); Pesticides.
Bibliography
Beek, Bernd. (2000). “Bioaccumulation: New Aspects and Developments.” In Handbook of EnvironmentalChemistry, Vol. 2: Reactions and Processes, Part J, edited by Otto Hutzinger. New York: Springer-Verlag. Colborn, Theo; Dumanoski, Dianne; and Myers, John Peterson. (1996). Our Stolen Future. NewYork: Dutton. Connell, Des W. (1990). Bioaccumulation of Xenobiotic Compounds. Boca Raton, FL: CRC Press. Internet Resource “Bioaccumulation and Biomagnification.” Available from http://www.marietta.edu/~biol.

Stefan Weigel

Biodegradation
Biodegradation is the decay or breakdown of materials that occurs when microorganisms use an organic substance as a source of carbon and energy. Forexample, sewage flows to the wastewater treatment plant where many of the organic compounds are broken down; some compounds are simply biotransformed (changed), others are completely mineralized. Thesebiodegradation processes are essential to recycle wastes so that the elements in them can be used again. Recalcitrant materials, which are hard to break down, may enter the environment as contaminants....