New insights into “forever chemicals” reveal how biochar could help clean up persistent pollution
image: Environmental behavior of per- and polyfluoroalkyl substances (PFASs) and the potential role of biochar for its remediation: a review
Credit: Haiyan Wang, Haiyan Zhang, Lizhi He, Jie Wang, Shuo Wang, Xiaoyu Shi, Xiaokai Zhang, Hailong Wang & Feng He
Per- and polyfluoroalkyl substances, widely known as PFAS or “forever chemicals,” have become a growing global concern due to their persistence, toxicity, and widespread presence in water, soil, and even food. A new review study highlights how biochar, a carbon-rich material derived from biomass, could play a key role in addressing this environmental challenge.
PFAS have been used since the 1940s in products ranging from textiles and food packaging to firefighting foams. Their strong carbon-fluorine bonds make them extremely resistant to degradation, allowing them to accumulate in ecosystems and living organisms. Studies have linked PFAS exposure to a range of health risks, including immune system disruption, reproductive effects, and potential carcinogenic outcomes.
The review synthesizes current knowledge on how PFAS behave in the environment and evaluates the potential of biochar as a sustainable remediation tool. The authors emphasize that PFAS can migrate through air, water, and soil, entering the food chain through contaminated drinking water and agricultural products. This widespread mobility makes effective remediation both urgent and challenging.
“PFAS contamination is particularly concerning because these compounds do not easily break down and can travel long distances in the environment,” said one of the study authors. “Our work provides a comprehensive understanding of how biochar can help control their spread and reduce their risks.”
Biochar, produced by heating organic materials such as agricultural residues under low-oxygen conditions, has attracted increasing attention as an environmentally friendly adsorbent. Compared to conventional materials, biochar is low cost, widely available, and can be tailored to improve its performance.
The review explains that biochar removes PFAS primarily through adsorption, a process in which contaminants attach to the surface of the material. Several mechanisms contribute to this process, including pore filling, hydrogen bonding, hydrophobic interactions, and electrostatic attraction. These mechanisms allow biochar to effectively capture PFAS molecules from water and soil.
In addition to adsorption, emerging evidence suggests that biochar may also promote the degradation of certain PFAS compounds under specific conditions. For example, biochar can generate reactive species such as free radicals under light exposure, which may help break down otherwise persistent contaminants. While this pathway is still under investigation, it points to new possibilities for enhancing remediation efficiency.
Importantly, the study highlights how biochar can reduce the transfer of PFAS into the food chain. By immobilizing these chemicals in soil and water, biochar limits their uptake by plants and aquatic organisms, thereby lowering potential human exposure.
However, the authors also note that the effectiveness of biochar depends on several factors, including its production conditions, surface chemistry, and environmental conditions such as pH and dissolved organic matter. Short-chain PFAS, for example, are generally more difficult to remove than long-chain compounds, presenting an ongoing challenge for researchers.
Despite these limitations, the review concludes that biochar represents a promising and sustainable approach for mitigating PFAS pollution. The authors call for further research to optimize biochar properties, better understand its long-term environmental impacts, and develop integrated treatment strategies.
As concerns about “forever chemicals” continue to grow worldwide, this work provides a timely and comprehensive roadmap for advancing green remediation technologies and protecting environmental and human health.
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Journal Reference: Wang, H., Zhang, H., He, L. et al. Environmental behavior of per- and polyfluoroalkyl substances (PFASs) and the potential role of biochar for its remediation: a review. Biochar 7, 14 (2025).
https://doi.org/10.1007/s42773-024-00410-6
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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.