BIOREMEDIATION
-Bioremediation refers to the process of using microorganisms to remove the environmental pollutants or prevent pollution.
-The removal of organic wastes by microbes for environmental clean-up is the essence of bioremediation.
-The other names used for bioremediation are biotreatment, bioreclamation and biorestoration.
-Xenobiotics broadly refer to the unnatural, foreign and synthetic chemicals such as pesticide, herbicide & other organic compounds.
TYPES OF BIOREMEDIATION :
1. Biostimulation
2. Bioaugmentation
3. Intrinsic bioremediation
1. Biostimulation
• The method in which bacteria are motivated to start the process of bioremediation.
• In this method, first the experts release nutrients and other important substances in the soil where there is need or removing the contaminants.
• These are in the form of gas or liquid. It increases the growth of microbes in that area.
• As a result bacteria and other microorganisms remove the contaminants quickly and efficiently.
2. Bioaugmentation
• Microorganisms that can clean up a particular contaminant are added to the contaminated soil and water.
• Bioaugmentation is more commonly and successfully used on contaminants removed from the original site, such as municipal waste water treatment facilities.
3. Intrinsic bioremediation
Process takes place in soil and water because these two places are always full of contaminants and toxins.
• This process is also called as natural attenuation.
• Also means use of the microorganisms to remove the harmful substances from soil and water.
• Especially those sites are treated with this method, which are underground, for example underground petroleum tanks.
Advantages:
• Low cost.
• Minimal site disruption.
• Simultaneous treatment of contaminated water and soil.
• Minimal exposure of public & site personnel.
• Useful for the complete destruction of a wide variety of contaminants.
• Can often be carried out on site, often without causing a major disruption of normal activities
• Can prove less expensive than other technologies that are used for cleanup of hazardous waste.
Disadvantages:
• Time consuming.
• Seasonal variation.
• Problematic addition of additives.
• 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.
• difficult to extrapolate (deduce) from bench and pilot-scale studies to fullscale field operations.
• Biological processes are often highly specific. microbial populations, suitable environmental growth conditions, and appropriate levels of nutrients and contaminants.
