Biochar offers a powerful, low-cost solution for emerging contaminants in soil and water
New review highlights how engineered biochar can tackle toxic metals threatening ecosystems and human health
image: Remediation of emerging inorganic contaminants in soils and water using pristine and engineered biochar: a review
Credit: Sabry M. Shaheen, Habib Ullah, Yuejun Wu, Ahmed Mosa, Yueru Fang, Yu Shi, Juan Liu, Manish Kumar, Han Zhang, Baogang Zhang, Ronghua Li, Jianxu Wang, Vasileios Antoniadis, Sang Soo Lee & Jörg Rinklebe
Emerging contaminants are rapidly becoming a global environmental challenge, posing risks to soil health, water quality, and human well-being. A new comprehensive review reveals that biochar, a carbon-rich material derived from biomass, may offer a sustainable and highly effective solution for removing these pollutants from the environment.
“Emerging inorganic contaminants are often overlooked, yet they can accumulate in soils and water and pose serious health risks,” said one of the study’s authors. “Our review shows that biochar, especially when engineered, has remarkable potential to immobilize and remove these toxic elements.”
The study focuses on a group of pollutants known as emerging inorganic contaminants, including vanadium, antimony, thallium, mercury, fluoride, and rare earth elements. These substances originate from industrial activities, mining, agriculture, and waste streams, and many are not yet fully regulated despite their toxicity. Once released, they can enter food chains, affect ecosystems, and harm human organs such as the liver, kidneys, and brain.
Biochar stands out as a promising remediation material due to its porous structure, high surface area, and rich surface chemistry. These properties allow it to capture contaminants through multiple mechanisms, including ion exchange, surface complexation, electrostatic attraction, and precipitation. Compared to conventional remediation methods, biochar is cost-effective, energy-efficient, and environmentally friendly.
The review highlights that while pristine biochar can remove contaminants, engineered or modified biochar performs significantly better. By introducing functional groups or incorporating metals such as iron or magnesium, scientists can tailor biochar to target specific pollutants. In some cases, modified biochar achieved near-complete removal of contaminants like vanadium or antimony in water systems.
Importantly, the effectiveness of biochar depends on several factors, including pH, redox conditions, and the chemical form of the contaminant. For example, certain metals may become more mobile under specific conditions, while others can be immobilized more effectively when biochar alters soil chemistry. This means that designing biochar for real-world applications requires careful consideration of environmental conditions.
Beyond direct adsorption, biochar can also enhance natural remediation processes. It can improve soil properties, increase microbial activity, and promote beneficial transformations of contaminants. In some cases, biochar supports microbial communities that convert toxic substances into less harmful forms, further reducing environmental risks.
Despite these promising findings, the authors emphasize that challenges remain. The performance of biochar can vary widely depending on its source material and production conditions. Additionally, more research is needed to understand long-term environmental impacts and to scale up applications for field use.
“This work provides a roadmap for developing next-generation biochar materials,” the authors noted. “With proper design and implementation, biochar could play a key role in sustainable environmental remediation.”
As concerns over pollution and water security continue to grow, biochar-based technologies may offer a practical and scalable pathway toward cleaner soils, safer water, and improved public health.
===
Journal Reference: Shaheen, S.M., Ullah, H., Wu, Y. et al. Remediation of emerging inorganic contaminants in soils and water using pristine and engineered biochar: a review. Biochar 7, 34 (2025).
https://doi.org/10.1007/s42773-024-00407-1
===
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.