Bioremediation

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 may be employed in order to attack specific contaminants, such as chlorinated pesticides that are degraded by bacteria, or a more general approach may be taken, such as oil spills that are broken down by the use of multiple techniques including the addition of nitrate and sulfate fertilizer to facilitate the decomposition of crude oil by indigenous or exogenous bacteria.

Related Topics:
Microorganism - Enzyme - Environment - Contaminant - Chlorinated - Pesticide - Bacteria - Oil spill - Nitrate - Sulfate - Fertilizer - Crude oil

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Not all contaminants are easily treated through the use of bioremediation; for example, heavy metals such as cadmium and lead are not readily absorbed or captured by organisms. The integration of metals such as mercury into the food chain may make things worse as organisms bioaccumulate these metals.

Related Topics:
Heavy metals - Cadmium - Lead - Mercury - Food chain - Bioaccumulate

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However, there are a number of advantages to bioremediation, which may be employed in areas that cannot be reached easily without excavation. For example, hydrocarbon spills (specifically, petrol spills) or certain chlorinated solvents may contaminate groundwater in the subsurface and injecting the appropriate organisms, in conjunction with electron acceptor or electron donor amendment, as appropriate, may significantly reduce contaminant concentrations after a period of time. This is typically much less expensive than excavation followed by disposal elsewhere, incineration or other ex situ treatment, and reduces or eliminates the need for pumping and treatment, which is a common practice at sites where hydrocarbons have contaminated groundwater.

Related Topics:
Excavation - Hydrocarbon - Petrol - Groundwater - Concentration - Incineration - Pump

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Generally, bioremediation technologies can be classified as in situ or ex situ. In situ bioremediation involves treating the contaminated material at the site while ex situ involves the removal of the contaminated material to be treated elsewhere. Some examples of bioremediation technologies are bioventing, landfarming, bioreactor, composting, bioaugmentation and biostimulation.

Related Topics:
In situ - Bioventing - Landfarming - Bioreactor - Composting - Bioaugmentation - Biostimulation

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