Could plentiful food waste be turned into a powerful water filter for removing heavy metals from the world’s key resource? (By libin for AdobeStock)
Key Points
Researchers at the FAMU-FSU College of Engineering compared two ways of turning food and agricultural waste into hydrochar, a carbon-rich material that can pull heavy metals such as copper out of water.
Modupe Ojewumi, a researcher in the Department of Civil and Environmental Engineering, led the study with Professor Gang Chen. Their paper, published in 2026 in the peer-reviewed journal Biomass, found that pressure-reactor carbonization and microwave-assisted carbonization produce hydrochar with different structures and different ways of capturing metals.
The findings could help engineers match a hydrochar production method to a specific water-treatment need rather than relying on trial and error.
Across Florida and around the world, access to clean water remains a pressing challenge as toxic heavy metals from factories and farms threaten the health of our communities and natural environment.
Researchers at the FAMU-FSU College of Engineering are exploring sustainable solutions, such as hydrochar, to remove these dangerous pollutants from water. A key question is how to improve hydrochar’s performance.
(Scott Holstein/FAMU-FSU College of Engineering)
Who is leading the hydrochar research at the FAMU-FSU College of Engineering?
Modupe Ojewumi, a researcher at Florida A&M University in the Department of Civil and Environmental Engineering at the FAMU-FSU College of Engineering, is pursuing that question in a new study published in the journal Biomass. She carried out the work with Professor Gang Chen, a faculty member at the college whose research focuses on hydrochar and environmental materials.
How does hydrochar turn food waste into a water filter?
Hydrochar forms when biomass, such as food scraps or crop residue, is heated in water under pressure, a process called hydrothermal carbonization.
“Food and agricultural waste or biomass can be turned into useful materials called hydrochar,” Ojewumi said. “Although hydrochar is good at getting pollutants out of the water, we want to find a way to improve how it does this. Using different carbonization methods, we think we can find better ways to process it to help it work better.”
“Converting food waste into hydrochar transforms a high-volume organic waste stream into a carbon-rich, value-added material,” Chen said. “It simultaneously advances waste diversion, carbon management, resource recovery and environmental sustainability.”
The researchers hope to design the material to capture harmful metals more effectively, offering a greener alternative to conventional treatment methods.
What is the difference between pressure-reactor and microwave-assisted carbonization?
(Scott Holstein/FAMU-FSU College of Engineering)
“In our research, we compare two carbonization methods—pressure reactor and microwave-assisted—to see how each one affects the structure of the hydrochar and how well each method can capture heavy metals from water,” Ojewumi said.
The first method, pressure-reactor carbonization (P-RC), produces hydrochar that is particularly effective at consistently capturing metals in one layer. This method is effective at removing heavy metals such as copper from water.
The second method, microwave-assisted carbonization (M-RC), enables the hydrochar to attract metals more quickly and through multiple mechanisms.
Why do these hydrochar findings matter for water treatment?
The findings suggest that researchers could tailor hydrochar materials to specific water-cleaning needs rather than relying on trial and error.
“Previous studies just looked at how well hydrochar performed, but our research digs deeper to find out why some types are better than others from the changes that happen during carbonization,” Ojewumi said.
The researchers envision a future where scientists choose a carbonization method based on the job at hand, producing materials better suited to removing specific metals and making water purification more efficient and sustainable.
The work is relevant to environmental engineers, materials scientists and water treatment specialists, particularly those working to turn waste into useful products. It also applies to industries and agencies dealing with heavy-metal contamination and to organizations pursuing circular-economy approaches to waste reuse.
Who funded the FAMU-FSU hydrochar study?
The National Science Foundation’s Excellence in Research program funded the project through an award to Florida A&M University.
Researchers completed the analytical work using instruments in FAMU’s School of the Environment.
Editor’s Note: This article was edited with a custom prompt for Claude Opus 5.5, an AI assistant created by Anthropic. The AI optimized the article for SEO/GEO discoverability, improved clarity, structure and readability while preserving the original reporting and factual content. All information and viewpoints remain those of the author and publication. This article was edited and fact-checked by college staff before being published. This disclosure is part of our commitment to transparency in our editorial process. Last edited: 10/22/2026.
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