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Bioremediation" can be defined as any process that uses microorganisms or their enzymes to return the environment altered
by contaminants to its original condition.
Bioremediation techniques are currently being used at hazardous waste sites. Specifically, they are applied to waste sites facilitating the clean up of biodegradable contaminants. The majority of environmental hazards in which Bioremediation has proved successful include those of oil spills, gasoline contaminations, chlorinated solvents and other toxic chemical leaks. Examples include the gasoline contamination in Galloway, New Jersey, the crude oil spill in Bemidji, Minnesota, the fuel leak in Hanahan, South Carolina, and the sewage effluent in Cape Cod, Massachusetts
Facts:
●The most vital factors that control the effectiveness of bioremediation are the permeability of the soil and the biodegradability of the organic compound,
●Fine-grained soils such as clays and silts have a lower permeability than coarse grain soils like sand and gravel.
●Bioremediation is cost competitive and requires 45-140 dollars per ton of soil to biodegrade (For certain types of bioremediation).
Bacteria involved: The bacteria involved in the process of bioremediation are simply gluttonous microbes.
-The optimal pH for the bacterial growth is approximately 7.
-Bacteria require a carbon source for cell growth and an energy source to sustain their metabolic functions, the nitrogen and phosphorus serve as an energy source and the carbon dioxide in the air is used as the carbon source.
Types of Bioremediation:
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In-Situ Remediation In-situ Bioremediation treats the
contaminated soil or groundwater in the location in which it is found. In this technology oxygen and occasionally nutrients are pumped under pressure into the soil through wells. These nutrients spread on the surface to infiltrate into the contaminated area of material or the saturated zone.
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Ex-Situ Remediation Ex-situ Bioremediation requires pumping of the groundwater or excavation of contaminated soil prior to remediation treatments. Ex-situ Bioremediation can be further broken down into two main components or processes; Slurry-phase and solid-phase treatment.
Advantages and Disadvantages:As to advantages, bioremediation is a “natural process”, it destroys the target chemicals, its’ usually less expensive than other technologies, and can be used where the problem is located. Disadvantages of bioremediation include the fact that little is still unknown concerning specifics on its effects in areas having multiple contaminations, it often takes longer than other treatment methods, and that it requires constant monitoring to ensure effectiveness.