Biochar for heavy metal cleanup in soil and water: a review

The increasing trend of heavy metals in soil and aquatic ecosystems, driven by urbanization and industrialization advancements, has raised environmental concerns. While various remediation methods exist, they often lack scalability and sustainability. Biochar has emerged as a promising solution due to its eco-friendly nature and multifunctional properties. In particular, engineered biochar, modified to enhance its surface area and functional groups, exhibits superior performance in heavy metal adsorption. Biochar’s diverse morpho-physicochemical features, such as increased surface area and cation exchange capacity, facilitate heavy metal adsorption through various processes. The choice of feedstock materials and modification methods significantly influences biochar’s sorption capacity. Numerous reviews address the toxicity and treatment methods for heavy metals in soil and water. This study aims to advance the research by identifying key challenges and offering insights into engineered biochar production, characteristics, and applications for heavy metal cleanup in soil and water ecosystems. By exploring biochar potential with suitable interventions, we can develop sustainable solutions to mitigate metal toxicity and protect environmental and public health. Further research is necessary to overcome limitations and challenges, addressing research gaps and future directions in utilizing biochar as an eco-friendly, cost-effective technology for heavy metal remediation.

Graphical Abstract