Students learn about a special branch of engineering called bioremediation, which is the use of living organisms to aid in the clean-up of pollutant spills. Students learn all about bioremediation and see examples of its importance. In the associated activity, students conduct an experiment and see bioremediation in action!

Bioremediation is a part of the environmental engineering field. It is a commonly-used practice that takes advantage of a natural process — living organisms. By using the pollutant as a food source, engineers can identify exactly which microorganism can help to break down a certain pollutant. chemicals bioremediation oil spill pollution bacteria environment After this lesson, students should be able to: Define bioremediation. Explain why bioremediation is a useful process for cleaning up pollutants. Imagine for a moment that you are an environmental engineer. There has just been a huge oil spill off the coast of California, and oil is spreading everywhere. The spill is causing a lot of damage to the ecosystem and to the animals that live in the area. How might you clean up the spill? (Give the students a few minutes to talk about a solution with their classmates. Some ideas they may come up with are: scoop up the oil in a net, absorb it on a paper towel, use bioremediation. After a few minutes, write down the ideas on the board. Maybe one of the students will have suggested bioremediation, even if they are not sure how it would work.) Great job everyone; these are excellent ideas! Another way that environmental engineers clean up pollutants is through a process called bioremediation. Who knows what this process means? Let's break it down. (Write the word "bioremediation" on board.) Who knows what "bio" means? (Solicit answers. For hints, have them think about the words "biology," "biography," etc.) Good! The prefix "bio" means "dealing with life." How about "remediation?" That reminds me of a different word that you all might be more familiar with: "remedy." Who here has heard of a cold remedy or allergy remedy? What do you think that means? (Wait for answers). A remedy is something that makes you feel better, right? It is something that cures or controls an illness or disease. So, does anyone have a guess of what bioremediation might be? (Answer: Bioremediation is the process of using small living things called microorganisms to clean up pollutants in the environment. Bacteria is an example of a microorganism.) Now let's think about that oil spill again. Engineers can add oil-eating bacteria to an oil spill, and those bacteria break down the oil and clean up the pollution. Why do you think that bioremediation would be a good process to use over other available technologies for treatment? (Possible answers: Lower cost, better for the environment, etc.) Bioremediation is the use of microbes to break down pollutants, odors or pests. Bioremediation involves taking advantage of the natural processes for the benefit of cleaning up. Bioremediation was invented by George M. Robinson in the 1960s. Robinson, working as the assistant county engineer for Santa Maria, California, organized the first large-scale microbial cleanup of an oil spill in 1968. Robinson used bioremediation to complete the clean up of spills, sewage, leach fields as well as odor and pest control. Today, microbes are used to treat sewage, oil spills, contaminated soil and increase yields in food production. Nearly every company that competes in this market place uses bug cultures that can be traced back to George Robinson or one of his colleagues. Bioremediation has been used in several famous cleanups such as the Exxon Valdez Oil Spill in Alaska in 1989. Alongside the many volunteers who worked to clean the 11 million gallons of spilled oil, microbes worked with them by breaking down oil as their food source. By applying specific microbes to a pollutant spill, engineers can help to speed up the process, minimizing the damage to the environment. Bioremediation Successes The U.S. Geological Survey has had tremendous success with bioremediation. Their practice of using bioremediation has contributed to the safe, effective cleanup of many spills, some dangerously toxic, as well as the advancement of bioremediation knowledge and know-how. Some of their successes are listed below. Crude oil spill, Bemidji, Minnesota: In 1979, a pipeline carrying crude oil burst and contaminated the underlying aquifer. USGS scientists studying the site found that toxic chemicals leaching from the crude oil were rapidly degraded by natural microbial populations. Significantly, it was shown that the plume of contaminated ground water stopped enlarging after a few years as rates of microbial degradation came into balance with rates of contaminant leaching. This was the first and best-documented example of intrinsic bioremediation in which naturally occurring microbial processes remediates contaminated ground water without human intervention. Sewage effluent, Cape Cod, Massachusetts: Disposal of sewage effluent in septic drain fields is a common practice throughout the United States. Systematic studies of a sewage effluent plume at Massachusetts Military Reservation (formerly known as Otis Air Force Base) led to the first accurate field and laboratory measurements of how rapidly natural microbial populations degrade nitrate contamination (denitrification) in a shallow aquifer. Chlorinated solvents, New Jersey: Chlorinated solvents are a particularly common contaminant in the heavily-industrialized Northeast. Because their metabolic processes are so adaptable, microorganisms can use chlorinated compounds as oxidants when other oxidants are not available. Such transformations, which can naturally remediate solvent contamination of ground water, have been extensively documented by USGS scientists at Picatinny Arsenal, New Jersey. Pesticides, San Francisco Bay Estuary: Pesticide contamination of rivers and streams is a matter of concern throughout the United States. Field and laboratory studies in the Sacramento River and San Francisco Bay have shown the effects of biological and non-biological processes in degrading commonly used pesticides, such as molinate, thiobencarb, carbofuran and methyl parathion. Agricultural chemicals in the midcontinent: Agricultural chemicals affect the chemical quality of ground water in many Midwestern States. Studies in the midcontinent have traced the fate of nitrogen fertilizers and pesticides in ground and surface waters. These studies have shown that many common contaminants, such as the herbicide atrazine, are degraded by biological (microbial degradation) and non-biological (photolytic degradation) processes. Gasoline contamination, Galloway, New Jersey: Gasoline is probably the most common contaminant of ground water in the United States. Studies at this site have demonstrated rapid microbial degradation of gasoline contaminants and have shown the importance of processes in the unsaturated zone (the zone above the water table) in degrading contaminants. The United States Geological Survey has had tremendous success with bioremediation. Their practice of using bioremediation has contributed to the safe, effective cleanup of many spills, some dangerously toxic, as well as the advancement of bioremediation knowledge and know-how. Some of their successes are listed below. The process of using microorganisms to clean up an environmental hazard. A chemical that causes harm to the environment. A life form that is so small, it can only be seen with a microscope. Sugar Spill! Bioremediation is an example of science and engineering working together to form a solution to a real-life problem. Scientists work to define what certain bacteria thrive on, whereas engineers develop processes to use those bacteria for the good of the environment. Using natural organisms helps to prevent further pollution and costly machinery from being involved in the clean up process. Definition Brainstorming: Have the students work in pairs to come up with a definition of bioremediation. Have them also discuss which kinds of engineers might be involved with the process. Voting: Ask a true/false question and have students vote by holding thumbs up for true and thumbs down for false. Count the votes and write the totals on the board. Give the right answer. True or False: Mechanical engineers are the engineers primarily involved with bioremediation. (Answer: False. Environmental engineers are the engineers primary involved with bioremediation, though other disciplines may also be involved.) True or False: Bioremediation is the use of micoorganisms for the clean up of pollutants. (Answer: True) True or False: Bioremediation is often a less expensive and more environmentally friendly clean-up process. (True) Where Else? Where else could bioremediation be used? Have the students think of other possible uses for bioremediation in their everyday lives. (Have them think about where in their lives chemicals or processes are used. Are there ways to do this naturally using bioremediation?) Have students engage in research to find an article related to bioremediation. They could present their findings in a report or in a short presentation. U.S. Department of Energy, Lawrence Berkeley Laboratory, accessed April 2, 2009. http://www.lbl.gov/publicinfo/newscenter/tabl/2009/march/03-16-09/bioremed-icon.jpg U.S. Department of the Interior, U.S. Geological Survey, Fact Sheet FS-054-95, "Bioremediation: Nature's Way to a Cleaner Environment," April 1, 1997, accessed April 2, 2009. http://water.usgs.gov/wid/html/bioremed.html#HDR1