Bioremedian Process

1. 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

2.  Bioaugmentation is the practice of adding cultured
microorganisms into the subsurface for the purpose of
biodegrading specific soil and groundwater
contaminants.
 Biostimulation involves the modification of the
environment to stimulate existing bacteria capable of
bioremediation. This can be done by addition of
various forms of rate limiting nutrients and electron
acceptors, such as phosphorus, nitrogen, oxygen, or
carbon (e.g. in the form of molasses).
 Bioventing is a process of stimulating the natural in
situ biodegradation of contaminants in soil by
providing air or oxygen to existing soil
microorganisms. Bioventing uses low air flow rates
to provide only enough oxygen to sustain microbial
activity in the vadose zone.

3. BIOREMEDIATION IS A TRIPLE-CORNERS PROCESS
Organisms
Pollutants
Environments
Microorganisms
Plants
Enzymes
Soil
Water
Air
Organic
Inorganic
Solid
Liquid
Gas

4. REDOX CLEAN-UP REACTIONS
 Anaerobic or aerobic metabolism involve oxidation and
reduction reactions or Redox reactions for detoxification.
 Oxygen could be reduced to water and oxidize organic
compounds. Anaerobic reaction can use nitrate.
 In return, biomass is gained for bacterial or fungal growth.
 In many cases, combined efforts are needed, indigenous
microbes found naturally in polluted sites are useful.

5. PSEUDOMONAS
 Genetically engineered bacteria (Pseudomonas) with
plasmid producing enzymes to degrade octane and many
different organic compounds from crude oil.
A selected list of genetically engineered microorganisms
GEMs XENOBIOTICS
Pseudomonas putida Mono-and dichloro
aromatic compounds
P.diminuta Parathion
P.oleovorans Alkane
P.cepacia 2,4,5-Trichlorophenol
Acinetobacter species 4-Chlorobenzene
Alcaligenes species 2,4-Dichlorophenoxy
acetic acid

6. USE OF FUNGI IN BIOREMEDIATION
 Candida can degrade formaldehyde.
 Gibberella can degrade cyanide.
 Slurry-phase bioremediation is useful too but only for small
amounts of contaminated soil.
 Composting can be used to degrade household wastes.
 White rot fungi can degrade organic pollutants in soil and
effluent and decolorize kraft black liquor, e.g. Phanerochaete
chrysosporium can produce aromatic mixtures with its
lignolytic system.
 Pentachlorophenol, dichlorodiphenyltrichloroethane (e.g.
DDT), even TNT (trinitrotoluene) can be degraded by white
rot fungi.
WHITE ROT FUNGI

7. ENVIRONMENTAL CLEAN-UP PROCESS
 The basis of removal and transportation of wastes for
treatment, basically there are two methods.
1.Insitu bioremediation
2.Ex situ bioremediation
 INSITU BIOREMEDIATION:
* It involves direct approach for the microbial
degradation of xenobiotics at the sites of pollution (soil, ground
water).
* It has been successfully applied for clean-up oil
spillages, beaches etc.
* There are 2 types of insitu bioremediation ,
‡ Intrinsic bioremediation
‡ Engineered bioremediation

8. EXSITU BIOREMEDIATION
* The waste or toxic materials can be collected from the
polluted sites and the bioremediation with the requisite
microorganisms can be carried out at designed places.
METABOLIC EFFECT OF MO’S ON XENOBIOTICS:
¤ Detoxification ¤ Activation
¤ Degradation ¤ Conjugation
TYPES OF REACTIONS IN BIOREMEDIATION:
» Aerobic bioremediation
» Anaerobic bioremediation
» Sequential bioremediation

9. BIOREMEDIATION OF HYDROCARBONS
 Petroleum and its products are hydrocarbons. Oil constitute a
variety of hydrocarbons (xylanes, naphthalenes, octane's, camphor
etc,).
 The pollutants can be degraded by a consortium of microorganisms,
e.g Pseudomoas, Corynebacterium, Arthrobacter, Mycobacterium
and Nocardia.
 Genetically engineered bacterial strains are used to enhance
bioremediation.
 In 1979, Anand Mohan Chakrabarty - obtained a strain of
Pseudomonas putida that contained the XYL and NAH plasmid as
well as a hybrid plasmid derived by recombinating parts of CAM
and OCT.
 In 1990, the USA Govt allowed him to use this superbug for
cleaning up of an oil spill in water of State of Texas. It was
produced on a large scale in laboratory, mixed with straw and dried.

10. Sewage from cities
Industrial effluents
Oil slick
Pollution from warships
Military activities
MARINE POLLUTION

11. MARINE POLLUTION

12. Oil spill
11 million gallon oil spill
from the supertanker
EXXON VALDEZ-
ALASKA in March-
1989.

13. Landfarming
(Ex-Situ remediation)

14. What is Landfarming?
Landfarming, also known as land
treatment or land application, is an
above-ground remediation technology
for soils containing hydrocarbon
contaminant through biodegradation.
As with other biological treatments,
under proper conditions, landfarming
can transform contaminants into
non-hazardous substances. Contaminated Soil Treatment

15. Bioremediation Technology
 It is a natural processes that cleans up harmful chemicals in the
environment.
 Microscopic “bugs” or microbes that live in soil and groundwater
like to eat certain harmful chemicals, such as those found in oil
spills.
 When microbes completely digest these chemicals, they change
them into water and harmless gases such as carbon dioxide.

16. Application
 This technology usually involves
spreading contaminated soils
in a thin layer on the ground
surface and stimulating
aerobic microbial activity
within the soils through aeration
and/or the addition of
minerals, nutrients, and
moisture.
 Each strip shall be clearly
marked on a board, by the
Contractor, with the following
information::
◦ Date of spreading
◦ Treatment applied
Each strip is recorded by marking the
date of spreading & treatment applied.

17. Operation Principles
 The effectiveness of landfarming depends on parameters that may be
grouped into four categories:
◦ soil characteristics
◦ constituent characteristics
◦ climatic conditions
◦ Soil texture which may affects moisture content, and bulk density of the
soil. For example, soils which tend to clump together (such as clays) are
difficult to aerate and result in low oxygen concentrations. It is also difficult
to uniformly distribute nutrients throughout these soils.
 Periodic soil samples are tested to check on how breakdown of the
contaminants is progressing.

18. Soil Condition
 Soil conditions are often controlled to optimize the rate of contaminant
degradation. Conditions normally controlled include:
◦ Moisture content (usually by irrigation or spraying).
◦ Aeration (by frequently tilling the soil, the soil is mixed and aerated).
◦ pH (buffered near neutral pH by adding crushed limestone or agricultural
lime).
◦ Other adjustment (e.g., Soil bulking agents, nutrients, etc.).
Tilling of strip as part of landfarming
Watering of strip as part of landfarming

19. SOIL SHREDDING

20. System Design
 Landfarm Construction includes:
◦ site preparation (grubbing, clearing and grading);
◦ Liners (if necessary);
◦ Leachate collection and treatment systems;
◦ Soil pretreatment methods (e.g., shredding, blending and pH control);
 To support bacterial growth, the soil pH should be within the 6 to 8 range,
with a value of about 7 (neutral) being optimal.
 Soil microorganisms require moisture for proper growth. Excessive soil
moisture restricts the movement of air through the subsurface thereby
reducing the availability of oxygen. In general, the soil should be moist but
not wet or dripping wet.

21. Advantages
 Simple to design
and implement.
 Short treatment
period (usually 6-9
months under
optimal conditions).
 Effective organic
constituents with
slow biodegradation
rates.
Treated soil healthy enough to grow plants

22. Disadvantages
 May not be affective for high
constituents concentration of
hydrocarbon (greater than
50,000ppm total petroleum
hydrocarbon).
 Requires a large land area for
treatment.
 May require bottom liner if
leaching from the landfarm is a
concern.
 Dust and vapour generation
during landfarm aeration may
pose air quality concerns.
Dust generated during tilling

23. Phytoremediation
 Use of green plants and other autotrophic
organisms to clean up and manage hazardous and
other wastes
 Includes bioremediation by heterotrophic bacteria
when plants provide carbon, nutrients, or habitat –
rhizodegradation
 Phytoextraction – accumulates metals in above
ground tissues for harvest
 Phytodegradation or transformation
 Phytocontainment and stabilization
 Phytovolatilization and other types

24. • Phytoremediation is use of plants for accumulation,
removal or conversion of pollutants.
PHYTOREMEDIATION
Phytoremediation
Phytostabilization
Phytotransformation Phytoextraction
Phytovolatilization Phytostimulation

25. TABLES

26. • Approximately 400 plant species have been classified as
hyperaccumulators of heavy metals, such as grasses,
sunflower, corn, hemp, flax, alfalfa, tobacco, willow,
Indian mustard, poplar, water hyacinth, etc.

27. The root exudates of these plants play an important role in
phytoremediation as it activate the surrounded microorganisms.
Genetic engineering are used as in case of BT protein or insect
pheromones producing plants to reduce the use of pesticides.

28. PHYTO-REMEDIATION
 Effective and low cost , environmental friendly.
 Soil clean up of heavy metals and organic compounds.
 Pollutants are absorbed in roots, thus plants removed
could be disposed or burned.
 Sunflower plants were used to remove cesium and
strontium from ponds at the Chernobyl nuclear power
plant.
 Transgenic plants with exogenous metallothionein (a
metal binding protein) used to remove metals .

29. Metals bioremediation
mechanisms
Solubilization
(Bioleaching)
Complexation
(Bioaccumulation)
(Biosorption)
Metal
immobilization
Precipitation
- H2S producing bacteria
- Siderophores.
- Metal reduction.
- Exopolysaccharide.
- Lipoproteins.
- Organic acids.
- Siderophores.
- Root exudates.

30. Industries
plastics, textiles,
microelectronics, wood
preservatives, refineries
etc.
Agrochemicals
Excessive use of fertilizers
and pesticides etc.
Waste disposal
sewage sludge leach ate
from landfill, fly ash disposal
etc.
Mining activities
smelting, river dredging,
mine spoils and tailings,
metal industries etc.
Atmospheric
deposition
urban refuse disposal,
hydrometallurgical
industries,
automobile exhausts,
fossil
fuel combustion etc.
Heavy metals
sources in the
environmental
SOURCES OF HEAVY METALS IN THE ENVIRONMET

31. The biosurfactants are chemical compounds characterized by
hydrophobic and hydrophilic (non-polar and polar) regions in
one molecule (amphipathic molecules).
Biosurfactants from bacteria, cyanobacteria, fungi and yeast
are classified into:
1. Glycolipids.
2. Lipopeptides.
3. Phospholipids.
4. Glycoproteins.
5. Polymeric biosurfactants.
BIOSURFACTANTS PRODUCING GEM
 A genetically engineered Pseudomonas aeruginosa.
 This new strain can produce a glycolipid emulsifier.
 It can reduce the surface tension of an oil water interface.
The reduced interfacial tension promotes biodegradation of
oils.
BIOSURFACTANTS

32. BIOREMEDIATION OF INDUSTRIAL WASTES
 A variety of pollutants are discharged in the environment from a
large no of industries & mills.
1. Bioremediation of Dyes
2. Bioremediation in the paper and pulp industry
BIOREMEDIATION OF CONTAMINATED SOILS & WASTE LANDS
SLURRY-PHASE BIOREACTOR LANDFARMING-BIOREMEDIATION

34. PREVENTION AND CONTROL OF POLLUTION
These activities are supported by a set of legislative and regulatory
promotional measures such as Policy Statement on Abatement of
Pollution, 1992; and the National Environment Policy, 2006.
The major actions on Abatement of Pollution and Environmental
Cleanup are as follows: Clean Technology (CT), Control of Pollution
(CP), Environment Education (EE), Environmental Impact Assessment
(IA), Environmental Information (EI), Environmental Information
System (ENVIS), Environment Research (RE), Forest Protection
(FPR), Hazardous Substances Management (HSM) , Climate
Change(CC) , Clean Development Mechanism (CDM).

35.  There is an immediate necessity for initiating an “All India Coordinated
project on Bioremediation of the Contaminated Sites” involving premier
institutions in this field for conducting large scale demonstration projects.
 Further, various departmental agencies and related ministries in India may
plan a joint action plan to launch bioremediation from Lab-Pilot –Field
scale projects at specific sites
Environmental
cleanup
Joint action of
Govt.(various
ministries and
their
departments)
Novel lab level
research
Pilot Scale
experiments
Possible All India coordinated bioremediation demonstration projects at specifi c sites

36. BIOREMEDIATION FROM LAB-PILOT –FIELD SCALE

37. Bioremediation is a natural process and is therefore perceived by the public.
Bioremediation is useful for the complete destruction of a wide variety of
contaminants.
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.
ADVANTAGES AND DISADVANTAGES
ADVANTAGES OF BIOREMEDIATION
Bioremediation can often be carried out on site, often without causing a
major disruption of normal activities.
Bioremediation can prove less expensive than other technologies that are
used for cleanup of hazardous waste.

38. 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. microbial populations, suitable
environmental growth conditions, and appropriate levels of nutrients and
contaminants.
It is difficult to extrapolate (deduce) from bench and pilot-scale studies to
fullscale field operations.
Bioremediation often takes longer than other treatment options.

39. Inorganic metal contaminants
Organic contaminants
Radioactive contaminants
Brake fern
Poplar tree
Indian mustard
Oil
spill
Groundwater
Soil
Polluted
groundwater
in
Polluted
leachate
Decontaminated
water out
Landfill
Willow tree
Phytoextraction
Roots of plants can absorb
toxic metals such as lead,
arsenic, and others and
store them in their leaves.
Plants can then be recycled
or harvested and
incinerated.
Phytodegradation
Plants can absorb
toxic organic
chemicals and break
them down into less
harmful compounds
which are stored or
released into the air.
Phytostabilization
Plants can absorb
chemicals and keep
them from reaching
groundwater or
nearby surface
water.
Rhizofiltration
Roots of plants with
dangling roots can absorb
pollutants such as
radioactive strontium-90
and cesium-137 and
various organic chemicals.
Sunflower
Phytoremediation
Groundwater
Soil

40. Trade-Offs
Phytoremediation
Advantages Disadvantages
Easy to
establish
Inexpensive
Can reduce
material
dumped into
land fills
Produces little
air pollution
compared to
incineration
Low energy use
Slow (can take
several growing
seasons)
Effective only at
depth plant
roots can reach
Some toxic
organic
chemicals may
evaporate from
plant leaves
Some plants can
become toxic to
animals
Tradeoffs of Phytoremediation