Mud, microplastics, and a mission: Meet Professor of Chemistry Tao Wu

From the shores of Lake Valentine to the lab, chemistry students are tackling global issues by researching microplastics—merging science and biblical stewardship.

By Meckenna Holman '18, content specialist

April 10, 2018 | 12 a.m.

Professor Tao Wu smiles in the Brushaber Commons at Bethel.

Associate Professor of Chemistry Tao Wu brings his passion for science and stewardship into the classroom and the field, mentoring students as they tackle global challenges like microplastic pollution.

Tao Wu, an associate professor of chemistry at Bethel, sits in a canoe with two research students on Lake Valentine, a prized part of the university’s 247-acre campus—but they’re not there for a summertime float. The team is collecting lakebed samples in an effort to gather new data on the presence of microplastics in soil.

“There are a lot of papers published about microplastics in the ocean, but not too much talk about inland areas—especially in Minnesota, where we have big cities and a lot of lakes,” Wu says when explaining why microplastics in dirt drew his attention. 

Microplastics are often invisible to the naked eye and are caused by the breakdown of larger plastic items or products manufactured at a small size. As an illustration, Wu holds up the tip of a mechanical pencil—five millimeters wide—to visualize the largest microplastics. Then he explains the thickness of a single strand of hair—about one micron—is the width of the smallest microplastics in the environment.

Microplastics in soil ultimately pose risks to human health because they can easily contaminate air and food. The microplastics in cloth materials, hairspray, or even water balloons, for example, release microplastics into the air, settle into the soil, and inevitably enter our lungs and digestive tracts. Without any ability for the body to break down these microparticles, the plastic aggregates and passes undigested through our system.

Wu is passionate about this research. “I try to persuade my students that we want to work to make the world better, because God gave us this responsibility,” Wu says. “But this work should be based on the science or the data that we collect.”

“It’s not just about transferring knowledge at Bethel. We also model how to live and how to learn.”

— Tao Wu, associate professor of chemistry

A scientist’s faith journey

Wu did not always believe in God or the mandate to care for His creation. He grew up in China learning about the history of Christianity, but he did not know a single Christian until his cousin and aunt moved to the United States and became Christians. Wu was both surprised and intrigued by their decision.

After earning a degree in geochemistry in China, Wu was given the opportunity to pursue his Ph.D. in geoscience in the United States, and he jumped at the chance. Wu’s co-adviser for his doctoral program in Wisconsin was a Chinese Christian who completely welcomed Wu into the Christian faith. Wu’s ride from the airport when he arrived in the country ended at a local Chinese church. He was overwhelmed by the sermons and the kindness of the community and even felt open to the gospel, but the decision to become a Christian felt rushed, and Wu resisted the pull of God on his heart. 

“I told myself it was too quick—I'd only been in the U.S. a few months,” Wu says. “In China, I had grown up hearing that only weak or desperate people needed religion. It felt like believing in something—even something that moved me—might be a kind of personal failure. So, that first year, I missed the opportunity.”

Despite Wu’s resistance, his Ph.D. co-adviser continued to invite Wu to Bible study during his time at school. At the same time, Wu was immersing himself in research techniques that would later define his work at Bethel. “We were collecting samples from the earth and water—soil, mud, everything—and learning how to treat and separate them,” he says. “A lot of what I use now—like density separation and extraction techniques—I became very familiar with during that time.”

Wu’s spiritual turning point came just as he and his fiancée Jing Fang, now an administrative assistant in Bethel’s Anderson Family College of Health Sciences, were about to marry in China. However, one month before marriage, he became seriously ill and was hospitalized with major gallbladder complications.

What struck Wu most, though, wasn’t just the medical ordeal or the delayed wedding—it was the unexpected outpouring of love. “People from the Chinese church came to visit me. I didn’t know them. They didn’t know me. But they came, they talked to me, they comforted me, they encouraged me,” he says. “That was the turning point. I really felt the love of God—love that came from the Bible, from Jesus Christ.”

Soon after leaving the hospital, Wu told his co-adviser he wanted to become a Christian. “He said all I needed to do was pray,” Wu says. He was baptized on December 15—and married twelve days later. “My wife was so worried during that time,” he says. “But God made everything work.”

Tao Wu with his wife, Jing Fang, and daughters Elisha and Yvonne, smiling outdoors in a grassy field.

Tao Wu with his wife, Jing Fang, and their daughters, Elisha and Yvonne, whose love and support inspire his work in both science and faith.

Empowering students through hands-on research

God continued to move in Wu’s professional life as he gained experience in many geoscience settings. One of the biggest draws for Wu to Bethel is the university’s small, relational learning environment and liberal arts education. He first experienced this kind of setting while teaching at a community college, where he realized that being an educator meant more than delivering lectures—it meant caring for students. “I was trained not just as a professor, but as a care provider,” he says. At Bethel, he’s found the same opportunity to invest deeply in students. “It’s not just about transferring knowledge at Bethel,” Wu says. “We also model how to live and how to learn.” 

Back on Lake Valentine, Wu’s journey comes full circle. The scientific techniques he learned during his Ph.D. program, the spiritual calling shaped in hospital halls, and the care-driven teaching model he embraces—all converge in his microplastics research, where science meets stewardship.

With samples collected, the work continues in the lab. Wu and his undergraduate research students begin by isolating microplastics from the soil and water using filtration and density separation techniques. 

Junior biochemistry and molecular biology and chemistry double major Karissa Nelson ’27 was drawn to the environmental and organic chemistry focus of Wu’s research. “I liked the environmental aspect but also the organic chemistry research on microplastics,” she says. She appreciates how Wu shares his experience while still giving students ownership. “He genuinely allowed this to be our research. He gives us recommendations but lets us make the final call.”

Biochemistry major Alex Michuda ’26 says working with Wu has been a great experience, both in class and in the lab. Through the research, he’s gained a new awareness of how widespread microplastics are, even in systems meant to reduce pollution. The scale of the issue motivates him. “It’s compelling that this is a problem that is only going to increase as time goes by,” he says. Michuda appreciates Wu’s guidance throughout the process: “It’s really nice to get his feedback on how we’re going through our process and how it compares to his past research.”

Alex Michuda ’26 stands in Lake Valentine, handing a sediment sample to Karissa Nelson ’27 in a canoe.

Biochemistry majors Alex Michuda ’26 and Karissa Nelson ’27 collect lakebed samples on Lake Valentine as part of Professor Tao Wu’s microplastics research—merging hands-on learning with stewardship of creation.

Once the lakebed samples are separated from the organic matter, the team hopes to do several different category analyses—looking at shape, color, and origin of the microplastic particles. They use two advanced instruments to identify the plastics: pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) and Raman spectroscopy. 

Machine learning and the future of environmental chemistry

In collaboration with Rollin King, a Bethel professor of chemistry focusing on computational chemistry, Wu is attempting to incorporate machine learning to identify unknown microplastic particles. They are building a database from the six most common types of recyclable plastics, usually identified by a number with the chasing arrow (recycle) symbol often found at the bottom of plastic items. Common items include plastic water bottles, milk jugs, food packaging, plastic bags, yogurt containers, and disposable cups. 

There are some commercial ways to do this sorting, but the process is expensive. Wu and King hope to create their own library of microplastic identification using the Py-GC/MS and Raman spectroscopy. Once that library is built, they plan to create a machine learning model, one that can begin to automatically recognize and classify microplastics in new, unknown samples.

The implications of their research could eventually affect policy changes, but for now the team is focused on the data—and letting the numbers speak for themselves. 

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