Bioremediation uses microorganisms like bacteria and fungi to degrade environmental pollutants into less toxic forms. It can occur in situ, with the contaminants treated on site, or ex situ by removing the contaminated soil or water for treatment. The mechanisms involve microbes breaking down pollutants for food and energy. Key types are bacterioremediation using bacteria, phytoremediation using plants, and mycoremediation using fungi. Bioremediation can transform or mineralize organic wastes into innocuous substances like carbon dioxide and water.

1. Bioremediation

2. • It comes from two words, such as “bio” means living,
and “remediate” means solving a problem. So, by
combining these two words, we can say,
“Bioremediation is the technique of solving a problem
using living organisms like microbes.”
• In other words, it is a part of biotechnology that deals
with the elimination of environmental contaminants by
using microbes—the main biological agents.
• Thus, the microorganisms used for the degradation of
such pollutants are called bioremediates.

3. • Nowadays, the food we are eating, the water
we are drinking and using in several other
works, the air we are breathing, or the land
we’re living on, everywhere pollutants are
present.
• According to a study of the environmental
protection agency (EPA), only a minimal
amount that is 10% of wastes are disposed of
correctly. From this, we can easily conclude
how much pollution exists in our ecosystem.

4. • There are commonly five different kinds of
contaminants, such as munitions wastes, organic
solvents, halogenated aromatic hydrocarbon,
pesticides, and Polyaromatic hydrocarbon (PAH).
• Thus, for removing such pollutants, the
bioremediation technique is the most sustainable
method. It does its work without affecting our
environment and in an economically friendly way.

5. History of Bioremediation
• Bioremediation’s first commercial application was made in
1972 for the Sun oil pipeline spill in Ambler, Pennsylvania.
• However, In the mid-1980s, the researchers emphasize the
bioengineering of the microbes used in the bioremediation
process, which didn’t reach the goal it had.
• After that, in the mid-1990s, scientists changed their minds
and switched to better reliance on natural microorganisms
and techniques to boost their functionality.

6. Bioremediation Factors
• So, various factors necessary for the process
of bioremediation are as follows;
• Microbial Population for the biological
degradation.
• Availability of contaminants to degrade.
• Environmental Factors such as temperature,
pH, nutrients, the presence of oxygen, and
other electron acceptors, and also the kinds of
soils.

7. Mechanism of Bioremediation

8. • The mechanism or the working procedure of
bioremediation is based on the activity of microorganisms
we use.
• Those living organisms degrade and take the organic
compounds such as carbon, electrons, source of cell-
building materials, and energy source for their growth and
reproduction.
• First, the contaminants are analyzed, and microorganisms
are chosen according to the constituents present in that so
that they can digest the pollutants easily.
• For this, the microbes are firstly examined, cultured, and
placed in the polluted environment.

9. • Moreover, the microbes then grow
enormously and consume all the organic
nutrients they found in the waste and convert
them into carbon dioxide and water. We can
take measures to improve the conditions.

10. Types of Bioremediation
• After knowing “what is Bioremediation,” now
let’s know the various types of
bioremediation. Bioremediation can be
classified according to the strategies applied,
the microorganisms used, and the degradation
process types.

11. Based on strategies applied
• So, according to the strategy employed, the
types of bioremediation is of two types such
as;
• In situ bioremediation
• Ex-situ bioremediation

12. In situ bioremediation
• In situ, bioremediation is a strategy where, without
excavation, we can treat the associated
groundwater together with soil in place.
• The in-situ remediation process extent from a partially
closed system to a completely open system.
• Examples of these techniques involve percolation,
bioventing, air sparging, pump and treat, and bio-
slurping.
• Percolation comprises of put on water, having nutrients
and perhaps a microbial inoculum, to the exterior of a
polluted part.
• It permits to filter into the soil and blend with the
groundwater.

13. • However, Bioventing is a technique of aeration of an
unsaturated area by installing a well for drawing a vacuum
on the soil with the associated blowers and pumps.
• Furthermore, Air sparging is just the opposite of bioventing,
otherwise called biosparging. It is the aeration of a
saturated area with contaminated soil by a flow rate of <5
m3/h per point.
• Also, the pump and treat are an in-situ technique where we
can remove and treat contaminated groundwater.
• Bioslurping is another strategy for purifying groundwater
and soil (having pollutants like petroleum hydrocarbons) by
combining bioventing of surface soil with vacuum-
enhanced free products.

14. Ex-situ bioremediation
• Furthermore, the ex-situ Bioremediation is
just opposite to the in-situ technique. Here
the contaminated soil and groundwater are
taken out from their original location for
treatment.
• Some examples of ex-situ bioremediation are
Land farming, compost piles irrigation, and
engineered biopiles.

15. • In the land farming process, we use the blend of
volatilization and biodegradation with indigenous
microbes to treat the soil contaminants by
degrading or transforming them.
• For enhancing water and air holding capacity, and
physical handling properties, we supplement the
soil with composting elements like manure, wood
chips, straw, etc. This is the process of compost
piles.

16. • In other ways, an ex-situ remediation
technique where the contaminated soils are
situated into piles or cells above the ground
and the microbial activities are stimulated
with aeration or addition of nutrients.
• Hence, we can employ both the in-situ and ex-
situ to unsaturated or saturated regions, but
there are some limitations for each technique.

18. Based on Microorganisms
• According to the microorganisms used,
bioremediation is classified into three types:
• Bacterioremediation
• Phytoremediation
• Mycoremediation

19. Bacterioremediation
• Bacterioremediation is a type of remediation,
where bacteria are bioremediants and can
treat various kinds of pollutants through in-
situ or ex-situ techniques.

20. Phytoremediation
• Phytoremediation utilizes several plants to
stabilize, remediate, reduce, or restore
contaminants in sediments, soil, water, etc.
• As these plants can store the heavy polluting
metals in their tissues, industries apply various
techniques such as phytoextraction or
phytoaccumulation, phytotransformation, or
phytodegradation, phytostabilization,
phytovolatilization, rhizofiltration, and
rhizodegradation.

21. Mycoremediation
• For decontaminating a zone, if we use various
fungi types, then the form of bioremediation
is called mycoremediation.
• Furthermore, a fungus is much known for its
degradation properties by their fungal mycelia
and hence developed this technique.

23. Based on Types of Degradation
• So, based on the principle of degradation,
bioremediation is of two types;
• Biotransformation
• Biomineralization

24. • Biotransformation
• In the biotransformation process, various organic
components are partially degraded, and the
remaining portion is transformed into various
other organic matters.
• Biomineralization
• Biomineralization is another type of
bioremediation where microorganisms digest and
convert organic waste nutrients into inorganic
materials like water, carbon dioxide, etc.

25. Advantages and Disadvantages of
Bioremediation
Various advantages of it involve:
• It is beneficial to degrade the pollutants from a
wide variety of contaminants and convert them
into non-hazardous forms from the hazardous
form.
• This technology can treat the contaminants in
their original location and thus the necessity to
transfer from one medium to another finished.
• Affordable and thus economy friendly.
• Environment friendly as well, because the output
we get is not harmful to the environment.

26. Various disadvantages of it:
• Limited to biodegradable compounds.
• Proper microbial population and proliferation
required. This is because biological
mechanisms are highly precise.
• It takes lots of time to accomplish the process.