This document discusses bioremediation, which uses microorganisms to remove pollution from soil, water, and air. There are two types of bioremediation - in situ, which treats pollution at the site, and ex situ, which treats pollution off site. In situ bioremediation can be intrinsic, using native microbes, or engineered, by adding nutrients or microbes. Ex situ involves removing contaminated material and treating it through methods like slurry phase bioremediation, which mixes soil and water, or solid phase bioremediation using land farming or piles. Bioremediation is effective but performance is difficult to evaluate and volatile organic compounds remain challenging to degrade.

1. BIOREMEDIATION
DILSHANA FATHIMA
M.Sc. BIOCHEMISTRY

2. INTRODUCTION
 Refers to the process of using micoorganism to remove
environmental pollution i.e, toxic waste found in soil,
water, air etc.
 The microbes saves as scavengers in bioremediation.
 The removal of organic waste by microbes for
environmental cleanup is the essence of bioremediation.
 Other names used for bioremediation are bio treatment,
bio reclamation & bio restoration.
 Used to treat contaminated media including water, soil &
subsurface material by altering environmental condition to
stimulate growth of microorganism & degrade the target
pollutants.

3.  Bioremediation is a triple corner process
pollutants
organismenvironment

4. TYPES
 The environmental cleanup procedure through
bioremediation can be achieved in 2 ways:
1. In situ bioremediation
2. Ex situ bioremediation

5. IN SITU BIOREMEDIATION
 Involves a direct approach for the microbial
degradation of xenobiotics at the site of pollution.
 Addition of adequate quantities of nutrients at the
site promotes microbial growth.
 When these microorganisms are exposed to
xenobiotics, they develop metabolic ability to
degrade them.
 The growth of microorganisms & their ability to
bring out biodegradation are dependent on the
supply of essential nutrients.
 In situ bioremediation has been successfully applied
for cleanup of oil spillages, beaches etc.

6.  There are 2 types of in situ bioremediation
1. Intrinsic in-situ bioremediation
2. Engineered in-situ bioremediation
1. Intrinsic in-situ bioremediation
 Inherent metabolic ability of the microorganism to
degrade certain pollutants.
2. Engineered in-situ bioremediation
 Inherent ability of microorganisms for biodegradation
is generally slow & limited.
 However by using suitable physico-chemical means,
bioremediation process can be engineered for more
efficient degradation of pollutants.

7. EX SITU BIOREMEDIATION
 The waste or toxic materials can be collected
from polluted sites & the bioremediation with
the requisite microorganism can be carried out at
designed places.
 This process is certainly an improvement over
in-situ bioremediation & has been successfully
used at some places.
 Ex-situ bioremediation can occur in 2 ways
1. Slurry phase bioremediation
2. Solid phase bioremediation

8. 1. Slurry phase bioremediation
 Contaminated soil is mixed with water & other
reagents in larger tank (bioreactor).
 Oxygen & nutrients are added into the mix, so
microorganism can have ideal environment to break
down contaminants.
 Once the process is complete, water is separated
from the soil.
 Soil is tested & replaced in the environment.

9. 2. Solid phase bioremediation
 Treats contaminated soil in an above ground treatment
centre.
 Conditions are controlled to ensure optimum
treatment can take place.
 Is easy to maintain but requires a lot of space &
process of decontamination takes longer.
 It includes land farming, soil bio-piles & composting.

10. IN-SITU
BIOREMEDIATION
EX-SITU
BIOREMEDIATION
ADVANTAGES
•Cost effective
•Minimal exposure to
public/site personnel
•Site of bioremediation
remains minimally
disrupted.
ADVANTAGES
•Better controlled
•More efficient process
•Time required is short
•Process can be
improved by
enrichment with
desired microorganism
DISADVANTAGES
•Time consuming
•Sites are directly
exposed to
environmental factors
•Microbial degrading
ability varies
seasonally.
DISADVANTAGES
•Very costly process.
•Sites of pollution are
highly disturbed.
•There may be
disposal problem
after the process is
complete.

11. EVALUATING BIOREMEDIATION
 Performance evaluation of bioremediation,
especially in-situ bioremediation in the field is
difficult due to,
 Uncertainity created by the matrix
 Contaminant heterogenity
 Inaccessibility to observation
 Expense of sampling
 Limitation of some measurements

12.  4 key pieces of evidence indicative of successful
bioremediation are:
 Documentation of loss of phenanthrene
 An increase in aqueous phase TIC
 Decrease in δ¹³ carbon of dissolved organic pool
 A correlation b/w the phenanthrene removal &
increase in number of phenanthrene degrading
bacteria.

13. BIOREMEDIATION OF VOLATILE
ORGANIC COMPOUNDS
 Volatile organic compounds(VOCs) are major air
pollutants which are released into the environment
through mobile sources, stationary sources, area sources
& natural sources.
 Various organisms that can degrade VOCs have been
reported.
 However, the biodegradation of VOCs remains a
challenging issue.
 Practical sites such as chemical factories, research
facilities & illegal dumping sites are often contaminated
with multiple VOCs.
 VOCs include chlorinated ethenes, BTEX & chlorinated
methane.

14.  Based on the concentration level of VOC,
several removal technique have been employed
to combat VOCs.
 Non biological methods such as ozonation,
absorption, adsorption, incineration,
condensation, membrane seperation are being
employed.
 Several biological methods ranging from
trickling filters to biofilters have been
demonstrated & they are found to be
economical.
 The biofilters are simple to construct, easy to
operate & cost effective.

15. THANK YOU