The ‘microbial analysis of sulfur-based autotrophic denitrification drainage systems’ is a mouthful, but this Biology and Engineering collaborative study at Elizabethtown College might help save future populations from swallowing a mouthful of harmful chemicals and deter harm to aquatic life.
Nitrate, a form of nitrogen, is found in groundwater, streams and lakes due, in part, to agricultural and industry runoff. When consumed through drinking water, preserved meats and a few edible plants, the body converts nitr-A-tes (NO3–) into nitr-I-tes (NO2–). In 
high quantities, nitrites can cause a variety of health issues in marine life and in humans, especially infants. Its concentration raises the risk of food allergies, asthma, hepatitis, gallstones and forms of cancer.
In addition, nitrates pose a significant ecological risk. Nitrates, in large supply, serve as nutrients to algae in receiving bodies of water such as the Chesapeake Bay and Gulf of Mexico, said Deb Wohl, professor of biology at Elizabethtown College. The algae flourish with this extra source of nitrogen but deplete oxygen when they die. This oxygen deficit, or hypoxia, harms aquatic life and the economic vitality of the surrounding communities.
Biology learns about engineering; engineering learns about biology.”
Elizabethtown College students are researching a concept that might help limit nitrates in waterways throughout the world.
Microorganisms—bacteria, viruses, fungi—consume nitrates. The E-town research explores how specially treated perforated tubing, already used to keep fields from flooding, can introduce microorganisms to limit the amount of nitrates in runoff, said Brenda Read-Daily, assistant professor of engineering and physics at Elizabethtown.
“For the engineers to remove the nitrates to receiving bodies of water,” she said, “they rely on a biological process. … It’s applying a design idea to an agricultural setting.”
“This is a real-world problem,” said Deb Wohl, professor of biology at Elizabethtown College, who is working with Read-Daily to offer a collaborative student experience. The collaboration, she said is a great opportunity for students to move from abstract problem solving to something that has tangible value.
Her hope, she said, is to get biology classes excited about working with engineers. In the work world, Wohl noted, biologists are often called on for environmental consulting. She used the example of assessing an environment based on the present biodiversity.
“Biology learns about engineering; engineering learns about biology,” said Read-Daily of the research. Engineering and science students, due to their course load, have a hard time taking classes outside their major, she said, so this is a way to cross-teach.
Beginning at the end of May and continuing through a summer Scholarship, Creative Arts and Research Projects grant, one biology and two engineering students will work with lab-scale tubing to collect samples of microbial data. Then, continuing in the fall and spring they will analyze the data. “They will analyze the data, watching for change and effect,” Wohl said,
The biology student, said Read-Daily, will be involved in analysis of the microbial community, sampling sulfur and extracting DNA. The DNA will be sequenced to see which microorganisms are in abundance and if there is a shift toward bacteria that can reduce nitrates over time. “A lot of sampling and examining,” she said.
Presently, tubing is placed underground so water is slowly reabsorbed into the earth or channeled toward a nearby body of water. The idea, Read-Daily said, is to use that concept but add a reactive layer of sulfur that microorganisms will grow on. In the end, drainage tubes will be engineered to convert nitrates to nitrogen gas, underground, before the runoff flows out into a stream or lake.
In the Midwest where it’s flat, said Read-Daily, there are “millions of miles of this tubing.”
If the study goes well, Read-Daily said, it’s a project that could be presented to the College’s Social Enterprise Institute for possible commercial use, especially in areas where excess nitrate pollution is a concern.