Zhang, Chen, et al (2024) 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 improved the solubility of triclocarban in aqueous environment: Insight into the role of biochar-derived dissolved organic carbon. Chemosphere. https://doi.org/10.1016/j.chemosphere.2024.141172

Biochar is known for its ability to remove harmful chemicals from wastewater. But a new study reveals a surprising twist: biochar can actually increase the solubility of some pollutants, potentially making them more mobile and risky.

The study focused on triclocarban, a common antibacterial found in soaps and cosmetics. The researchers made biochar from pine sawdust and corn straw under different conditions, and then tested how well it removed triclocarban from water.

Here’s the surprising part: Biochar made at lower temperatures (300-450°C) actually increased the water solubility of triclocarban, up to 3 times more than without biochar! This was due to a dissolved carbon component in the biochar, called BC-DOC, which acted like a tiny ferry, carrying triclocarban around in the water.

However, biochar made at higher temperatures (600-750°C) didn’t have this effect. Instead, it absorbed triclocarban directly, thanks to its strong surface and chemical interactions.

So, what does this mean? It depends on the pollutant and the biochar you use. While high-temperature biochar can be effective for removing some chemicals, low-temperature biochar could actually make things worse for others. It’s important to carefully consider the type of pollutant and the properties of the biochar before using it for water treatment.

Here are some key takeaways from the study:

• Biochar made at different temperatures can have different effects on pollutant solubility.
• Some biochar can actually increase the mobility of certain pollutants in water.
• We need to carefully choose the right biochar for the job to avoid unintended consequences.

This study highlights the importance of understanding the complex interactions between biochar and pollutants