Bioremdiation of Toxic Wastes

Essay by chronicidalJunior High, 7th gradeA+, February 2004

download word file, 3 pages 4.3

Bioremediation, or biodegradation, is a method that uses microscopic organisms to reduce, eliminate, or contain hazardous wastes into less harmful substances [NABIR 9]. It has only been a popular and an important waste treatment method since the late 1980's [Hunt]. Hazardous substances such as polycyclic aromatic hydrocarbons (PAHS), petroleum, and polychlorinated biphenyls (PCBs) can pollute the environment after not being properly disposed of, mishandled, or accidentally spilled. Among the most prevalent metallic substances in Department of Energy toxic waste are chromium, lead, mercury, plutonium, uranium, cesium, strontium, and technetium. The last five are highly radioactive [NABIR 9].

Bioremediation offers a cheaper, more efficient approach to clean nature. Other techniques such as incineration, ocean dumping, land filling, or deep-well injections are all either expensive and/or dangerous. Piling up toxic and radioactive waste underground or in the ocean bed can lead to contamination of the water or the soil [Kronenwetter 56-65].

Bioremediation technology in a way started in 1891 when the first biological sewage treatment plant opened in Sussex, UK.

Merriam-Webster dates the word only to 1986. 'Bioremediation' was first used in peer-reviewed scientific literature in 1987 [NABIR 9]. Bioremediation first got in the public spotlight when the Exxon-Valdez oil tanker spilled 11 million gallons of crude oil into the Price William Sound and on the Alaskan coastline. The Environmental Protection Agency and Exxon decided to stimulate growth of indigenous bacteria along the shore using nitrogen and phosphorous fertilizers. The bacteria would help in lap up the hydrocarbons and the oil eventually gets diluted and dissipated into the marine environment [Anderson 4]. This is known as in situ bioremediation. "In situ" is Latin for "in place of". "Ex situ" means out of its original place. "Ex situ" usually refers to processing waste after pumping it to a bioreactor or other place of...