Role of microbes in bioremediation waseem microbiology

3. Roles of microbes in Bioremediation
Presented by
Hafsa, Saqib, Asif Afzal

4. Contents
• Bioremediation
• How it works?
• Essential Factors for microbial Bioremediation
• Bioremediation Methods & Types
• Microbes involved in Bioremediation
• Advantages & Disadvantages of Bioremediation
• Application of Bioremediation
• Some Bioremediation related technologies.
• Conclusion
• References

5. "Remediate" means to solve a problem, and "bioremediate" means to use
biological organisms to solve an environmental problem such as
contaminated soil or groundwater.
• Bioremediation means to use a biological remedy to abate or clean up
contamination.
• Bioremediation is a waste management technique that involves the use of
organisms to remove or neutralize pollutants from a contaminated site.
• According to the EPA, bioremediation is a “treatment that uses naturally
occurring organisms to break down hazardous substances into less toxic or
non toxic substances”.
What is Bioremediation?

6. What is Bioremediation?
• Bioremediation is the a biological degrading processes for the treatment of contaminated soils, groundwater and/or sediments,
relying on microorganisms including bacteria and/or fungi to use the contaminant(s) as a food source with resulting degradation of
the contaminant.
• Microorganisms used to perform the function of bioremediation are known as
bioremediators.
• Bioremediation is one of the most economic remedial techniques presently available for treating most organic fuel based
contaminants such as coal tars and liquors, petroleum and other carcinogenic hydrocarbons such as benzene and naphthalene, and
some inorganics.

8. How Does It Work?
• Waste material is examined & certain bacteria
are isolated based on their efficacy at digesting
and converting the waste.
• Indigenous or local bacteria is to be used!
• The bacteria then go through several steps of
cultures and process for performance testing.
• The suitable bacteria are placed back in the
waste environment.
• They grow & thrive & in the process digest &
convert the waste into Carbon dioxide & water.
• The right temperature, nutrients, and food also
must be present.
• Conditions may be improved by adding
“amendments.”

9. ESSENTIAL FACTORS FOR MICROBIAL BIOREMEDIATION
Factor Desired Conditions
Microbial population Suitable kinds of organisms that can biodegrade all of the contaminants
Oxygen Enough to support aerobic biodegradation (about 2% oxygen in the gas phase or 0.4
mg/liter in the soil water)
Water Soil moisture should be from 50–70% of the water holding capacity of the soil
Nutrients Nitrogen, phosphorus, sulfur, and other nutrients to support good microbial growth
Temperature Appropriate temperatures for microbial growth (0–40˚C)
pH Best range is from 6.5 to 7.5

11. TYPES OF BIOREMEDIATION :
1. Biostimulation 2. Bioaugmentation 3. Intrinsic Bioremediation
• 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.
• 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.
• 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.

12. 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.

13. 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

17. Applications of Bioremediation

18. In-situ bioremediation of soil:
• Allows treatment of a large volume of soil
at once.
• Mostly effective at sites with sandy soils.
• Can vary depending on the method of
supplying oxygen or electron donors to the
organisms that degrade the contaminants.
• Three commonly used in-situ methods
include:
Bioventing
Injection of hydrogen peroxide or oxygen
releasing compound (ORC) for aerobic treatment
Injection of HRC for anaerobic treatment
Ex-situ Bioremediation of soil:
• Involves excavation of the contaminated soil
and treating in a
treatment plant located on the site or away from the
site.
• This approach can be faster, easier to control, and
used to treat a wider range of contaminants and soil
types than in situ approach.
• Ex-situ bioremediation can be implemented as:
 Slurry-phase bioremediation, or
 Solid-phase bioremediation
• Contained Solid Phase
• Composting
• Land farming
Bioremediation of Contaminated Soil

19. Bioremediation of Contaminated Soil

20. Bioremediation of Aquifer
• In situ bioremediation (ISB) of groundwater involves the encouragement of indigenous bacterial populations to
metabolize target contaminants through the addition of various amendments (biostimulation) to the subsurface
environment.
• In addition to amendments, select strains of bacteria may be added to the subsurface to help treat some sites
(bioaugmentation).
• Bacteria perform coupled oxidation/reduction (redox) reactions to live, and bioremediation exploits these reactions
to remove contaminants from contaminated media (groundwater).

21. • Bacteria can use different electron acceptors (oxidized compounds) and donors (reduced compounds) in the
three major oxidation pathways —
• Aerobic respiration,
• Anaerobic respiration, and
• Fermentation.
• ISB can use all of these pathways, and contaminant degradation may occur through
• Direct metabolism,
• Cometabolism, or
• Abiotic transformations that may result from biological activities
Bioremediation of Aquifer

22. Bioremediation of Aquifer

23. Bioremediation of Marine Oil Spills
• Useful process for removing marine oil pollutants.
• The application of oleophilic fertilizer is a useful bioremediation strategy.
• Marine oil spills are very catastrophic events which pose a great threat on the affected environment.
• Marine oil spills are mainly oils, petroleum, fuel etc. composed of complex hydrocarbons.
• Addition of microbial seeding or inoculum that are capable of degrading hydrocarbons.
• Most microorganisms considered for seeding are obtained from enriched cultures (from a previously contaminated
site).
• After inoculum addition, fertilizer is added, then environmental modification is done , adequate aeration, nutrient
source is a prerequisite.
• Bioremediation for marine oil spills can be approached in two different ways depending on the case at hand. This
includes bioaugmentation which involves introducing oil degrading microorganisms to the affected site, and also
biostimulation which involves adding supplemental nutrients to the affected site to aid the existing oil degrading
microorganisms.

24. Bioremediation of Marine Oil Spills

25. Bioremediation of Marine Oil Spills

26. Bioremediation of Air Pollutants

27. Bioremediation of Air Pollutants
• Microorganisms are used for air emission control in 3
types of devices:
a. Biofilter
b. Bioscrubbers
c. Trickling Filter

28. Bioremediation related technologies
• Phytoremediation - bioremediation through the use of plants that mitigate the environmental problem
without the need to excavate the contaminant material and dispose of it elsewhere.
• Bioventing - an in situ remediation technology that uses microorganisms to biodegrade organic constituents in the
groundwater system.
• Bioleaching - the extraction of metals from their ores through the use of living organisms.
• Landfarming - an ex-situ waste treatment process that is performed in the upper soil zone or in biotreatment cells.
• Bioreactor - any manufactured or engineered device or system that supports a biologically active
environment.
• Vermicomposting - using various worms, usually red wigglers, white worms, and other earthworms to
create a heterogeneous mixture of decomposing vegetable or food waste, bedding materials, and
vermicast.
• Rhizofiltration - is a form of phytoremediation that involves filtering water through a mass of roots to
remove toxic substances or excess nutrients.

29. Conclusion:_
· Bioremediation is a eco-friendly technology .
· It is effective process.
· Recovery of contaminated medium by using living microorganisms.
· Approach to enhance the degrading capability.
· Application in all types of contaminated fields.

30. References
• Microbial Ecology by Atlas & Bartha
• Various Webpages including:
• Wikipedia
• http://ei.cornell.edu/biodeg/bioremed/
• http://www.pollutionissues.com/A-Bo/Bioremediation.html
• http://www.soilutions.co.uk/services/soil-remediation/bioremediation/
• http://www.slideplayer.com/slide/1523117/#
• http://krockne.people.uic.edu/proceeding9.pdf
• https://cluin.org/download/remed/introductiontoinsitubioremediationofgroundwater_dec2013. pdf
• http://home.engineering.iastate.edu/~tge/ce421-521/matt-r.pdf
• A Citizen’s Guide To Bioremediation