A newly engineered biochar material could offer a powerful and low-cost way to remove toxic pollutants from wastewater, according to a new study published in Biochar. By combining simple chemicals during production, researchers created a material that dramatically improves the performance of advanced oxidation processes widely used in water treatment.
“Our goal was to design a biochar that not only works better, but also helps us understand why it works better,” said the study’s corresponding author. “We found that combining urea and sodium carbonate creates a synergistic effect that fundamentally changes how the material interacts with pollutants.”
Biochar, a carbon-rich material made from biomass, has attracted growing attention for environmental cleanup because it is inexpensive, sustainable, and versatile. However, unmodified biochar often lacks sufficient reactive sites and electron transfer capacity, limiting its effectiveness in activating oxidants such as peroxymonosulfate, a chemical used to break down persistent organic contaminants.
To address this challenge, the research team developed a co-modified biochar by heating a mixture of corncob, urea, and sodium carbonate in a one-step process. The resulting material, referred to as NABC, showed significantly enhanced structural and chemical properties compared to conventional biochar.
Laboratory tests revealed that the new material could completely degrade aniline, a toxic industrial compound, within 30 minutes when used in combination with peroxymonosulfate. Its reaction rate was more than five times higher than that of unmodified biochar.
The researchers found that the improvement was not simply due to higher surface area, although that played a role. Instead, the key lies in how the two modifying agents work together at the molecular level.
Urea introduces nitrogen into the biochar structure, creating active sites that enhance chemical reactivity. At the same time, sodium carbonate promotes the formation of highly ordered graphitic carbon structures and helps retain oxygen-containing functional groups such as carboxyl groups. These features improve electron transfer and stabilize the interaction between the catalyst and oxidant.
Importantly, the co-modified biochar also changes how reactive oxygen species are generated during the treatment process. Traditional systems rely heavily on hydroxyl radicals, which can be inefficient and easily quenched. In contrast, the new material favors the production of singlet oxygen and superoxide radicals, which are more selective and effective for degrading certain pollutants.
“This shift in reaction pathway is critical,” the author explained. “It means we can achieve faster and more efficient degradation with potentially lower energy and chemical input.”
The study also showed that the system performs well across a range of pH conditions and is resistant to interference from common ions in water, suggesting strong potential for real-world applications.
Advanced computational modeling further confirmed that graphitic nitrogen and carboxyl groups act as key active sites, working together to lower energy barriers and enhance electron transfer during pollutant degradation.
Beyond its immediate application in wastewater treatment, the research provides new insights into how biochar materials can be rationally designed for improved performance.
“This work offers a clear strategy for tailoring biochar at the molecular level,” the author said. “It opens the door to more efficient and sustainable solutions for tackling emerging contaminants in water.”
As global concerns over water pollution continue to grow, innovations like this could help bridge the gap between laboratory research and scalable environmental technologies.
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Journal Reference: Zhou, T., Zhu, S., Li, X. et al. Unraveling the synergistic mechanism of urea and sodium carbonate during biochar modification and peroxymonosulfate activation for wastewater decontamination. Biochar 7, 35 (2025).
https://doi.org/10.1007/s42773-025-00433-7
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About Biochar
Biochar (e-ISSN: 2524-7867) is the first journal dedicated exclusively to biochar research, spanning agronomy, environmental science, and materials science. It publishes original studies on biochar production, processing, and applications—such as bioenergy, environmental remediation, soil enhancement, climate mitigation, water treatment, and sustainability analysis. The journal serves as an innovative and professional platform for global researchers to share advances in this rapidly expanding field.
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