In a recent review published in The Canadian Journal of Chemical Engineering, Soumik Chakma and colleagues explore the latest advancements in biochar’s design, synthesis, and modification for remediating heavy metal pollution in water. The review emphasizes how tailoring biochar’s properties through production methods and modifications can significantly enhance its effectiveness in removing pollutants.  

The key takeaway is that biochar’s adsorption capacity is heavily influenced by production parameters. For example, biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More produced from lignin-rich feedstocks has a higher carbon content, while cellulose-rich feedstocks improve the porous structure. Furthermore, higher pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More temperatures (500-700°C) generally increase the surface area and porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More, enhancing physical adsorption. The authors suggest that an optimal balance between temperature and functional group retention maximizes biochar’s adsorption efficiency.  

The review also discusses how modifying biochar with magnetic nanoparticles improves pollutant adsorptionBiochar has a remarkable ability to attract and hold onto pollutants, like heavy metals and organic chemicals. This makes it a valuable tool for cleaning up contaminated soil and water.   More and recovery. Different methods, including pre-pyrolysis, co-pyrolysis, and post-pyrolysis treatments, can achieve this. For instance, co-pyrolysis is highlighted as a straightforward and cost-effective method.  

Ultimately, the effectiveness of biochar in heavy metal removal depends on its high surface area, various functional groups, and porous structure. The authors conclude that optimizing biochar synthesis and modification can lead to more sustainable and efficient wastewater treatment solutions.  

SOURCE: Chakma, S., Hasan, M., Rakshit, S. K., Kozinski, J., & Kang, K. (2025). Review of recent advances in the design, synthesis, and modification of biochar for remediation of heavy metal pollution in water. The Canadian Journal of Chemical Engineering, 103(1), 1-27.