Bioremediation: Difference between revisions

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It has become an accepted remedy to clean-ups due to its safety and convenience. The process relies on the microorganisms that are natural to the soil, and also allows scientists to solve the problem right at the site of contamination. [1] Bioremediation processes typically involve many different microbes acting in parallel or sequence to complete the degradation process. The ability of microbes to degrade a vast array of pollutants makes bioremediation a widely applicable technology that can applied in different soil conditions [3].   
It has become an accepted remedy to clean-ups due to its safety and convenience. The process relies on the microorganisms that are natural to the soil, and also allows scientists to solve the problem right at the site of contamination. [1] Bioremediation processes typically involve many different microbes acting in parallel or sequence to complete the degradation process. The ability of microbes to degrade a vast array of pollutants makes bioremediation a widely applicable technology that can applied in different soil conditions [3].   


Pollutants found in soils present a variety of different human health risks including direct toxicity, as well as bioaccumulation in plant and animal tissue eventually consumed by humans[3].  A number of priority pollutants and their origins is found below:
Pollutants found in soils present a variety of different human health risks including direct toxicity, as well as bioaccumulation in plant and animal tissue eventually consumed by humans.  A number of priority pollutants and their origins is found below [3]:


1) BTEX - benzene, toluene, ethylbenzene, and xylene - byproducts of petroleum products. The biodegradability of these compounds is relatively well known and remediation can be achieved by creating favorable conditions for BTEX degrader's growth.
1) BTEX - benzene, toluene, ethylbenzene, and xylene - byproducts of petroleum products. The biodegradability of these compounds is relatively well known and remediation can be achieved by creating favorable conditions for BTEX degrader's growth.


2)MBTE -  
2)MBTE - Methyl-butyl ether is a gasoline additive introduced to replace lead. MBTE raises the oxygen content of fuel, allowing for more complete combustion and less emissions. MBTE, however, is highly soluble, does not adsorb well in soil and can therefore move quickly through soil and into groundwater.





Revision as of 08:53, 12 February 2008

Introduction

Bioremediation refers to the use of microorganisms to degrade contaminants that pose environmental, and especially human risks. It has become an accepted remedy to clean-ups due to its safety and convenience. The process relies on the microorganisms that are natural to the soil, and also allows scientists to solve the problem right at the site of contamination. [1] Bioremediation processes typically involve many different microbes acting in parallel or sequence to complete the degradation process. The ability of microbes to degrade a vast array of pollutants makes bioremediation a widely applicable technology that can applied in different soil conditions [3].

Pollutants found in soils present a variety of different human health risks including direct toxicity, as well as bioaccumulation in plant and animal tissue eventually consumed by humans. A number of priority pollutants and their origins is found below [3]:

1) BTEX - benzene, toluene, ethylbenzene, and xylene - byproducts of petroleum products. The biodegradability of these compounds is relatively well known and remediation can be achieved by creating favorable conditions for BTEX degrader's growth.

2)MBTE - Methyl-butyl ether is a gasoline additive introduced to replace lead. MBTE raises the oxygen content of fuel, allowing for more complete combustion and less emissions. MBTE, however, is highly soluble, does not adsorb well in soil and can therefore move quickly through soil and into groundwater.


New applications of bioremediation continue to be developed to degrade hazardous chemicals, although there are similarities between approaches.

Bioremediation Applications

Examples

Degradation Pathways

Advantages/Possibilities

Monitoring

Key Microorganisms

Pseudomonas putida is a gram-negative soil bacterium that is involved in the bioremediation of toulene, a component of paint thinner. It is also capable of degrading naphthalene, a product of petroleum refining, in contaminated soils. [2]


Industrial bioremediation is used to clean up wastewater. Most treatment systems rely on microbial activity to remove unwanted compounds from the wastewater, for example fixed nitrogen compounds (i.e. ammonia). The reduction of ammonia to dinitrogen gas involves two different microbes. First, Nitrosomonas europaea reduces ammonia to nitrite. Then, Paracoccus denitrificans reduces nitrite to dinitrogen gas. Therefore, the nitrogen pollution in the wastewater is eliminated as the gas escapes to the atmosphere. Denitrification is the process of consuming fixed forms of nitrogen as the electron acceptor in anaerobic conditions and reducing it to dinitrogen gas [2].

References

1. United States Environmental Protection Agency, "A Citizen's Guide to Bioremediation" 2001.

2. Nitrification and Denitrification Wastewater Treatment. No. 5536407. 16 July 1996. <http://www.google.com/patents?id=F9UZAAAAEBAJ>

3. Sylvia, D. M., Fuhrmann, J.F., Hartel, P.G., and D.A Zuberer (2005). "Principles and Applications of Soil Microbiology." New Jersey, Pearson Education Inc.

Edited by student of Kate Scow