Transcript Bioremediation Basics

Bioremediation
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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
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What Is Bioremediation?
• 1980 Superfund Program established by U.S.
Congress
– Initiative of the U.S. Environmental Protection Agency
(EPA)
– To counteract careless and even negligent practices of
chemical dumping and storage, as well as concern over
how these pollutants might affect human health and the
environment
– Purpose is to locate and clean up hazardous waste sites
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What Is Bioremediation?
• Environmental Genome Project
– Purpose is to study and understand the impacts of
environmental chemicals on human disease
• 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
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What Is Bioremediation?
• Biotechnological approaches are essential for
– Detecting pollutants
– Restoring ecosystems
– Learning about conditions that can result in human
diseases
– Converting waste products into valuable energy
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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
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Bioremediation Basics
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Bioremediation Basics
• Chemicals in the Environment
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Carcinogens
Mutagens
Cause skin rashes, birth defects
Poison plant and animal life
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Bioremediation Basics
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Bioremediation Basics
• Fundamentals of Cleanup Reactions
– Microbes convert chemicals into harmless substances by
either
• Aerobic metabolism (require oxygen) or anaerobic
metabolism (do not require oxygen)
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Bioremediation Basics
• Aerobic and Anaerobic Biodegradation
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Bioremediation Basics
• The Players: Metabolizing Microbes
– Indigenous microbes – those found naturally at a polluted site
– Bacteria
• Pseudomonas
• E.coli
– Algae and fungi
• Phanerochaete chrysosporium
• Phanerochaete sordida
• Fusarium oxysporum
• Mortierella hyaline
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Bioremediation Basics
• 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 assist indigenous microbes
with biodegradative processes
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Cleanup Sites and Strategies
• Soil Cleanup
– Ex situ bioremediation
• Slurry phase bioremediation
• Solid phase bioremediation
– Composting
– Land farming
– Biopiles
– In situ bioremediation
• Bioventing – pumping either air or hydrogen peroxide into
the contaminated soil
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Cleanup Sites and Strategies
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Cleanup Sites and Strategies
• Bioremediation of Water
– Wastewater treatment
– Groundwater cleanup
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Cleanup Sites and Strategies
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Cleanup Sites and Strategies
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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
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Cleanup Sites and Strategies
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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
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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 RDX and TNT
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Environmental Disasters: Case Studies in
Bioremediation
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Jet Fuel and Hanahan, South Carolina
The Exxon Valdez Oil Spill
Oil Fields of Kuwait
BP Oil Spill in Gulf of Mexico
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Future Strategies and Challenges for
Bioremediation
• Recovering Valuable Metals
• Bioremediation of Radioactive Wastes
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