Advantages of bioremediation
•
Bioremediation is a natural process and is therefore perceived by the public as
an acceptable waste treatment process for contaminated material such as soil.
Microbes able to degrade the contaminant increase in numbers when the
contaminant is present; when the contaminant is degraded, the biodegradative
population declines. The residues for the treatment are usually harmless
products and include carbon dioxide, water, and cell biomass.
•
Theoretically, bioremediation is useful for the complete destruction of a wide
variety of contaminants. Many compounds that are legally considered to be
hazardous can be transformed to harmless products. This eliminates the chance
of future liability associated with treatment and disposal of contaminated
material.
• Instead of
transferring contaminants from one environmental medium to another, for
example, from land to water or air, the complete destruction of target
pollutants is possible.
•
Bioremediation can often be carried out on site, often without causing a major
disruption of normal activities. This also eliminates the need to transport
quantities of waste off site and the potential threats to human health and the
environment that can arise during transportation. • Bioremediation can prove
less expensive than other technologies that are used for clean-up of hazardous
waste.
Disadvantages of bioremediation
•
Bioremediation is limited to those compounds that are biodegradable. Not all
compounds are susceptible to rapid and complete degradation.
• There are
some concerns that the products of biodegradation may be more persistent or toxic
than the parent compound.
• Biological
processes are often highly specific. Important site factors required for
success include the presence of metabolically capable microbial populations,
suitable environmental growth conditions, and appropriate levels of nutrients
and contaminants.
• It is
difficult to extrapolate from bench and pilot-scale studies to full-scale field
operations.
• Research
is needed to develop and engineer bioremediation technologies that are
appropriate for sites with complex mixtures of contaminants that are not evenly
dispersed in the environment. Contaminants may be present as solids, liquids,
and gases.
•
Bioremediation often takes longer than other treatment options, such as
excavation and removal of soil or incineration.
• Regulatory
uncertainty remains regarding acceptable performance criteria for
bioremediation. There is no accepted definition of “clean”, evaluating
performance of bioremediation is difficult, and there are no acceptable
endpoints for bioremediation treatments.
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