Danhui Xin is a doctoral student and DENIN fellow working with professor Pei Chiu on biochar’s electron transfer and storage properties for "potential applications in drinking water disinfection, irrigation and storm water treatment, and soil remediation." [DENIN website] - (Evan Krape / University of Delaware)

Danhui Xin sets up a chemical reaction using biochar in an anaerobic glove box.

Earth Day: Danhui Xin

Article by Joy Drohan, Eco-Write, LLC Photos by Evan Krape and iStock | Illustration courtesy of NASA April 22, 2019

Delaware Environmental Institute Fellow trying to demystify chemistry of biochar

Biochar remains mysterious to most people, if they know of it at all. Not so with Danhui Xin.

“Biochar is seeing wide use these days, but it’s viewed as almost a magic powder,” said Xin, a University of Delaware doctoral student and Delaware Environmental Institute (DENIN) Fellow. Her research aims to increase the scientific understanding behind why and how biochar works.

Biochar is a carbon-rich product made by burning organic wastes. It is used for water treatment, soil remediation and soil fertility improvement.

Xin wants to understand the chemical properties that make biochar work. She is trying to quantify biochar’s electron storage capacity, which is a measure of biochar’s ability to mediate chemical and microbiological reactions.

“We still have a limited understanding of how exactly and to what extent this process happens,” Xin said. “If we understood more clearly what was happening as biochar degrades a contaminant, we could design a system that works exactly as expected.”

She said she thinks that the most promising use of biochar currently seems to be in removing contaminants such as nitrogen from water, which is important to the health of the Chesapeake Bay and other waterways, and therefore, to aquatic life.

Xin earned bachelor’s and master’s degrees in environmental engineering at Tongji University in Shanghai, China. During her master’s work, she studied at the University of Tokyo in Japan for about six months. After her master’s degree, she stayed on as a research assistant at Muroran Institute of Technology in Japan and studied waste treatment. She came to realize that different countries have very different ways of addressing water and waste problems, and wanted to see how western countries address these issues.

Xin came to UD to work with Pei Chiu, professor of civil and environmental engineering in the College of Engineering, because his research is about understanding the why and how behind transformation of environmental contaminants and providing engineering solutions.

When she’s done with her doctorate in a couple years, Xin said she hopes to stay in academia in the United States because she really enjoys research. She is also interested in commercializing a biochar product. She hopes to help bridge environmental research and technologies between the U.S. and East Asia. Her fluency in Chinese, Japanese, Korean, and English will surely help.

Xin mentors undergraduates in the engineering program and in Chiu’s lab. She has run a half marathon and enjoys hiking, yoga, and Chinese calligraphy.