This document is a submission from Waqas Azeem to Dr. Sher Muhammad Shahzad regarding the basic problem of releasing hazardous materials into the environment. It discusses how enormous quantities of organic and inorganic compounds are released each year through human activities. The release can be deliberate, accidental, or unavoidable. The EPA estimated in 1980 that over 57 million metric tons of total waste fell into three categories: heavy metals, chlorinated hydrocarbons, and nuclear waste. The document then provides details on bioremediation, the use of microorganisms to degrade pollutants, describing the requirements, types (in situ and ex situ), examples, advantages and disadvantages.

3. Submitted To
Dr. Sher Muhammad Shahzad
Submitted By
Waqas Azeem
Reg No
PAGF12E033
University College of Agriculture
University of Sargodha

4. THE BASIC PROBLEM:
RELEASE OF HAZARDOUS MATERIALS
 Enormous quantities of organic & inorganic
compounds are released into the environment each year
as a result of human activities.
 The release may be:
 Deliberate and well regulated (industrial emissions)
 Accidental and largely unavoidable (chemical/oil
spills)
 US EPA estimated that in 1980 at least 57 millions
metric tons of the total waste can be categorized into
three general groups:

5. 
Heavy metal, Pb, Cd, Ni and Be can accumulate in
various organs, interfere with normal enzymatic reactions
and cause disease including cancer

Chlorinated hydrocarbons, also known as organochlorides
including pesticides and other organic compounds such
as PCB (polychlorinated biphenyls)
 Research proven a positive correlation between cancer
in lab animals and organochlorides.

Nuclear waste including radioactive material such as
plutonium which are dangerous for thousands of years

6. What Is Bioremediation?
 Biodegradation - the use of living organisms such as
bacteria, fungi, and plants to degrade chemical
compounds
 Bioremediation – process of cleaning up
environmental sites contaminated with chemical
pollutants by using living organisms to degrade
hazardous materials into less toxic substances

7. What are environmental contaminants?
 pollutants
 naturally-occurring
compounds in the
environment that are
present in unnaturally high
concentrations.
 Xenobiotics
 chemically synthesized
compounds that have never
occurred in nature.
 Examples:

 Examples:




crude oil
refined oil
phosphates
heavy metals


pesticides
herbicides
plastics

8. Contaminants Potentially Amenable to Bioremediation
____________________________________________
Readily
degradable
____________
_
Somewhat
Difficult to
Generally
degradable
degrade
recalcitrant
_____________ _____________ _____________
fuel oils, gasoline creosote, coal
tars
chlorinated
solvents (TCE)
dioxins
ketones and
alcohols
pentachlorophenol (PCP)
some pesticides
and herbicides
polychlorinated
biphenyls (PCB)
monocyclic
aromatics
bicyclic aromatics
(naphthalene)

9. Current Situation in Pak
Pak is an agricultural country. But still most of its
agricultural fields are already deficient in fertilizer and
pesticides application. So, soil toxicity due to fertilizer or
pesticides application are very rare.
But water contamination cases can be seen.

10.  Karachi, a hub of industrial activity, houses seven
major industrial estates in
Korangi, Landhi, SITE, Federal B Area, North
Karachi, Superhighway and Port Qasim.
 At present, Karachi coastal region has become a
dumping ground of hazardous waste, receiving huge
quantities of untreated domestic & industrial
wastewater through Lyari & Malir Rivers.
 Since most industries have no treatment facility or have
grossly inadequate arrangements.
.

11.  Accelerated rate of fresh water contamination in the
city is exposing the problem of water scarcity.
 Continued practice will ultimately threatens fresh
water availability and food security for future as well
as health hazards and economic losses.

12. Current Concern
 Contaminated water is responsible for over 12 million
deaths per year world over.
 More than 40% hospital beds in Pakistan are
occupied by patients with water related diseases.
 According to Economic Survey of Pakistan 2008-09,
economic losses due to water pollution in the country
are estimated at Rs.109.5 billion per year.
 While National Drinking Water Policy Document 2009
mentions the same at about Rs.112 billion per year,
over Rs.300 million a day, in terms of health costs
and lost earnings.

13. Water Pollution in Karachi
 Karachi, population over 18 million discharged around
446 MGD of wastewater.
 About 70% untreated wastewater discharged into the
Arabian sea.
 All most all chemical waste are dumped untreated into
storm-drains, open nallahs or in the lyari and malir
rivers which ultimately fall into the Arabian Sea.
 The coastal zone, extended up to 135 Km, is exposed to
heavy pollution load of both domestic and industrial
origin.

14. With new regulations and a greater
environmental concern, industrial effluent
treatment need especial attention.

15. Why use Bioremediation?
 Most approaches convert harmful pollutants into
relatively harmless materials such as carbon
dioxide, chloride, water, and simple organic
molecules
 Processes are generally cleaner

16.  Biotechnological approaches are essential for
 Detecting pollutants
 Restoring ecosystems
 Learning about conditions that can result in human
diseases
 Converting waste products into valuable energy

17. BIOREMEDIATION
 It requires the control and manipulation of microbial
processes in surface reactors or in the subsurface.
 The contaminants can be biodegraded in situ or
removed and placed in bioreactor (at or off the
contamination sites).
 Idea:
 To isolate microbes that can degrade or eat a
particular contaminant
 To provide the conditions whereby it can do this most
effectively, thereby eliminating the contaminant

18. Bioremediation Basics
 What needs to be cleaned up?
 Soil, water, air, and sediment
 Pollutants enter environment in many different ways
 Tanker spill, truck accident, ruptured chemical tank
at industrial site, release of pollutants into air
 Location of accident, the amount of chemicals
released, and the duration of the spill impacts the
parts of the environment affected

19. Groundwater contamination
 Groundwater constitutes 96% of available
freshwater in U.S.
 95% of potable water in rural areas of U.S. comes
from groundwater
 In 1988, EPA confirmed that 26 states had various
amounts of 44 different pesticides in their
groundwater
 Cost of cleanup is in the $ trillions
 Issues that are still hotly debated
 How clean is clean?

20. Bioremediation Basics

21. REQUIREMENTS FOR BIOREMEDIATION
MICROORGANISMS
ENERGY
SOURCE
ELECTRON
ACCEPTOR
MOISTURE
NUTRIENTS
ABSENCE OF
TOXICITY
pH
TEMPERATURE
REMOVAL OF
METABOLITIES
ABSENCE OF
COMPETITIVE
ORGANISMS
BIOREMEDIATION

22. Microbial Divisions
 Two kinds of cells are recognized, the prokaryotic and
eukaryotic.
Prokaryotic cell
Eucaryotic cell
Bacteria
Blue-green bacteria or
cyanobacteria
Plants
Animals
Protozoa
Fungi
Most algae
 The most important groups to bioremediation are bacteria
and fungi.

23. Microorganisms
 Aerobic bacteria:
 Examples include: Pseudomonas, Sphingomonas,
Rhodococcus, and Mycobacterium
 Shown to degrade pesticides and hydrocarbons; alkanes
and polyaromatics
 May be able to use the contaminant as sole source of carbon
and energy.
 Methanotrophs:
 Aerobic bacteria that utilize methane for carbon and
energy
 Methane monooxygenase has a broad substrate range
 active against a wide range of compounds (e.g.
chlorinated aliphatics such as trichloroethylene and 1,2dichloroethane)

24.  Anaerobic bacteria:
 Not used as frequently as aerobic bacteria
 Can often be applied to bioremediation of
polychlorinated biphenyls (PCBs) in river
sediments, trichloroethylene (TCE), and chloroform
 Fungi:
 Able to degrade a diverse range of persistent or toxic
environmental pollutants

25. Aerobic and Anaerobic Biodegradation

26. Environmental Factors
 Nutrient availability
 Environmental Conditions
 Metal content

27.  Microorganisms destroy organic contaminants in
the course of using the chemicals for their own
growth and reproduction.
 Organic chemicals provide:
carbon, source of cell building material, electrons,
source of energy

28. TYPES OF BIOREMEDIATION
 The two main types of bioremediation are in situ
bioremediation and ex situ bioremediation. In
addition, another offshoot of bioremediation is
phytoremediation.

29. Forms of Bioremediation
 In situ Bioremediation






Bioventing
In situ biodegradation
Biostimulation
Biosparging
Bioaugmentation
Natural Attenuation
 Ex situ Bioremediation




Land farming
Composting
Biopiles
Bioreactors

30. In Situ Bioremediation
 In situ bioremediation is when the contaminated site is
cleaned up exactly where it occurred.
 It is the most commonly used type of bioremediation
because it is the cheapest and most efficient, so it’s
generally better to use.
 There are two main types of in situ bioremediation:
intrinsic bioremediation and accelerated
bioremediation.

31. Five Steps of In Situ
Bioremediation
1.
Site investigation
2. Treatability studies
3. Recovery of free product and removal of the
contamination source
4. Design and implementation of the in situ
bioremediation system
5. Monitoring and performance evaluation of the in
situ bioremediation system

32. Intrinsic Bioremediation
 Intrinsic bioremediation uses microorganisms
already present in the environment to biodegrade
harmful contaminant.
 There is no human intervention involved in this type
of bioremediation, and since it is the cheapest means
of bioremediation available, it is the most commonly
used.
 When intrinsic bioremediation isn’t feasible, scientists
turn next to accelerated bioremediation.

33. Accelerated Bioremediation
 In accelerated bioremediation, either substrate or
nutrients are added to the environment to help break
down the toxic spill by making the microorganisms
grow more rapidly.
 Usually the microorganisms are indigenous, but
occasionally microorganisms that are very efficient at
degrading a certain contaminant are additionally
added.

34.  Main advantage is that site disturbance is
minimized, which is particularly important when
the contaminated plume has moved under
permanent structures.
 Biggest limitation of in situ treatment has been the
inability to deal effectively with metal
contaminants mixed with organic compounds.
 The goal of in situ treatment is to manage and
manipulate the subsurface environment
optimize microbial degradation.
to

35. In Situ Bioremediation
 Land treatments:
Bioventing is the most common in situ treatment
and involves supplying air and nutrients
through wells to contaminated soil to stimulate
the indigenous bacteria.

36. Bioventing

37. In situ biodegradation involves supplying oxygen
and nutrients by circulating aqueous solutions
through contaminated soils to stimulate naturally
occurring bacteria to degrade organic contaminants.

38.  Stimulating Bioremediation
 Nutrient enrichment (fertilization) – fertilizers are
added to a contaminated environment to stimulate
the growth of indigenous microorganisms that can
degrade pollutants
 Bioaugmentation (seeding) –bacteria are added to
the contaminated environment to support
indigenous microbes with biodegradative processes

39. Biosparging involves the injection of air under pressure
below the water table to increase groundwater oxygen
concentrations and enhance the rate of biological
degradation of contaminants by naturally occurring
bacteria.
Biosparging increases the mixing in the saturated zone
and thereby increases the contact between soil and
groundwater.

40. Biosparging

41. Ex Situ Bioremediation
 which is when contaminated land are taken out of
the area to be cleaned up by the organisms.
 This type of bioremediation is generally used only
when the site is threatened for some reason, usually
by the spill that needs to be cleaned up.
 Ex situ bioremediation is only used when necessary
because it’s expensive and damaging to the area,
since the contaminated land is physically removed.

42. Cleanup Sites and Strategies

43. Ex Situ Bioremediation
Landfarming is a simple technique in which
contaminated soil is excavated(dig up) and spread over a
prepared bed and periodically tilled until pollutants are
degraded.
Composting is a technique that involves combining
contaminated soil with non-hazardous organic
compounds such as agricultural wastes.
The presence of these organic materials supports the
development of a rich microbial population and elevated
temperature characteristic of composting.

44. Landfarming
& Compost

45.  Bioreactors-Slurry reactors or aqueous reactors are
used for ex situ treatment of contaminated soil and
water pumped up from a contaminated plume.
 Bioremediation in reactors involves the processing of
contaminated solid material (soil, sediment, sludge)
or water through an engineered containment system.

47. Advantages and Disadvantages
Advantages of bioremediation
 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.

48. Adv
 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

49. Advantages and Disadvantages
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.

50.  Biological processes are often highly specific.
microbial populations, suitable environmental
growth conditions, and appropriate levels of
nutrients and contaminants.
 Bioremediation often takes longer than other
treatment options.

51. Cleanup Sites and Strategies
 Turning Wastes into Energy
 Methane gas used to produce electricity
 Soil nutrients can be sold commercially as fertilizers
 Anaerobes in sediment that use organic molecules
to generate energy

Electicigens – electricity-generating microbes.. ?

52. Applying Genetically Engineered Strains to Clean
Up the Environment
 Petroleum-Eating Bacteria
 Created in 1970s
 Isolated strains of pseudomonas from contaminated
soils
 Contained plasmids that encoded genes for
breaking down the pollutants

53. Applying Genetically Engineered Strains to Clean
Up the Environment
 E. coli to clean up heavy metals
 Copper, lead, cadmium, chromium, and mercury
 Biosensors – bacteria capable of detecting a variety of
environmental pollutants
 Genetically Modified Plants and Phytoremediation
 Plants that can remove TNT

54. Future Strategies and Challenges for
Bioremediation
 Recovering Valuable Metals
 Bioremediation of Radioactive Wastes

55. Thanks for your attention!