Bioremediation

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

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

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

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

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

Bioremediation Basics

Bioremediation Basics Chemicals in the Environment Carcinogens Mutagens Cause skin rashes, birth defects Poison plant and animal life

Bioremediation Basics

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)

Bioremediation Basics Aerobic and Anaerobic Biodegradation

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

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

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

Cleanup Sites and Strategies

Cleanup Sites and Strategies Bioremediation of Water Wastewater treatment Groundwater cleanup

Cleanup Sites and Strategies

Cleanup Sites and Strategies

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

Cleanup Sites and Strategies

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

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

Environmental Disasters: Case Studies in Bioremediation Jet Fuel and Hanahan, South Carolina The Exxon Valdez Oil Spill Oil Fields of Kuwait BP Oil Spill in Gulf of Mexico

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