A recent study in the Journal of Environmental Management explores how thermal air oxidation (TAO) affects the surface functionality of biochar, a carbon-rich material with numerous environmental applications. Researchers used in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and thermogravimetric analysis (TGA) to monitor changes in biochar produced at varying temperatures during the TAO process.

The study found that biochar’s surface functionality, particularly oxygenated functional groups (OFGs) such as carboxyl and ketone groups, changes significantly during TAO. Biochar produced at lower temperatures tends to form more carboxyl and lactone groups, while higher-temperature biochar shows greater resistance to oxidation and favors ketone formation. Additionally, intrinsic minerals present in biochar can act as catalysts, accelerating the TAO process and increasing mass loss.

TAO represents a promising method to modify biochar, enhancing its performance in applications like 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 energy storage. The researchers highlight that a deeper understanding of the TAO process could lead to more efficient biochar engineering, tailored to specific environmental uses. By focusing on preparation temperature and the role of minerals, this study provides valuable insights for optimizing biochar surface functionality, which is critical for its effectiveness in real-world applications.