Soil contamination is a major environmental threat, and scientists are searching for eco-friendly solutions. Biochar, a charcoal-like substance made from plant materials, emerges as a promising green sorbent for soil remediation. But how sustainable is it truly?

This review highlights the importance of Life Cycle Assessment (LCA) in evaluating biochar’s environmental impact. Recent studies (2021-2023) confirm its potential for reducing greenhouse gases and storing carbon, but concerns remain.

Key areas of uncertainty include:

• Impact on pollutants: Does biochar affect the mobility of heavy metals and pesticides in soil? More research is needed on optimal application frequency for pollutant removal.
• Soil carbon: How does biochar influence existing soil carbon stocks and different soil types?
• Biochar variability: Different production methods create biochar with varying properties, affecting its effectiveness and environmental footprint.
• Long-term effects: Limited long-term studies raise questions about potential health risks and the complete picture of pollutant dynamics.
• Soil surface albedo: Biochar’s dark color might impact soil temperature and reflectivity, requiring further investigation.

The review stresses the need for LCAs of other green sorbents like clay and chitosan, and proposes combining multiple green remediation techniques for improved efficiency.

By addressing these knowledge gaps and promoting comprehensive LCAs, researchers can ensure biochar truly lives up to its promise as a sustainable solution for cleaner soil and a healthier environment.