New study reveals biochar’s hidden power to tackle groundwater pollution
image: Modulating biochar compositions to maximize synergy between contaminant binding and transformation: the critical role of carbonates and implications for in situ groundwater remediation
Credit: Lin Duan, Zicui Gong, Yang Li, Tianchi Cao, Tong Zhang & Wei Chen
Scientists have discovered that tweaking the composition of biochar, a charcoal-like material made from biomass, can significantly improve its ability to trap and neutralize toxic groundwater contaminants. The findings, published in Biochar, could pave the way for more cost-effective and sustainable approaches to cleaning up long-lasting pollution from chlorinated solvents.
Groundwater contamination with chlorinated industrial chemicals, such as 1,1,2,2-tetrachloroethane (TeCA), poses persistent risks to ecosystems and human health. Traditional remediation methods like chemical oxidation or thermal treatments can be effective at removing large amounts of contaminants but are often too expensive or impractical for dealing with the low concentrations that linger for decades.
Researchers from Nankai University tested different pine wood–derived biochars produced at temperatures ranging from 300 to 700 °C. They discovered that biochars produced at higher temperatures (600–700 °C) not only adsorb contaminants more quickly, but also accelerate their breakdown into less harmful compounds. Surprisingly, the key to this enhanced performance was not the commonly assumed surface chemical groups, but rather the carbonate minerals formed during high-temperature pyrolysis.
“These carbonates act like microscopic catalysts, speeding up the chemical reactions that transform pollutants into substances that bind even more strongly to the biochar,” said co-corresponding author Prof. Wei Chen. “It means that biochar isn’t just a sponge—it’s also an active player in contaminant detoxification.”
In the case of TeCA, the reaction produces trichloroethylene (TCE), which the high-temperature biochars capture much more effectively than the original contaminant. Computer modeling showed that using such biochars in permeable reactive barriers could cut the material required by more than fivefold, dramatically reducing costs for long-term remediation.
The study highlights an overlooked advantage of biochar: its inorganic residues. Unlike activated carbon or costly engineered nanomaterials, biochar is low-cost, abundant, and can be tailored through feedstock selection and production conditions.
“Our work shows that by understanding and harnessing these hidden properties, we can design smarter, greener strategies for managing persistent groundwater contamination,” added co-corresponding author Prof. Tong Zhang.
The researchers note that future studies should assess how naturally occurring groundwater constituents influence biochar performance and explore ways to regenerate its capacity for reuse.
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Reference:
Duan L, Gong Z, Li Y, Cao T, Zhang T*, Chen W*. Modulating biochar compositions to maximize synergy between contaminant binding and transformation: the critical role of carbonates and implications for in situ groundwater remediation. Biochar (2025). https://doi.org/10.1007/s42773-025-00475-x
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Media Contact:
Wushuang Li
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About Biochar
Biochar 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.