Biochar’s Hidden Effect: Speeding Up Microplastic Aging

This research reveals a hidden side effect of biochar: its released organic matter speeds up the photoaging of microplastics in water. Understanding this complex interaction is key to tackling the growing challenge of microplastic pollution and ensuring the sustainability of water treatment practices.

January 20, 2024

1–2 minutes

Guo, Lyu, et al (2023) Self-motivated photoaging of microplastics by biochar-dissolved organic matter under different 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. *Science of the Total Environment, Vol 915.* https://doi.org/10.1016/j.scitotenv.2024.170043

Microplastics (MPs), tiny plastic fragments polluting our environment, undergo aging, breaking down into even smaller pieces with potentially harmful consequences. This research explores the surprising role of biochar-derived dissolved organic matter (BDOM) in this process.

Key Findings

BDOM, released from 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 used for water treatment, significantly accelerates the photoaging of polystyrene MPs under light.
Low-temperature BDOM is the most effective aging booster, causing MPs to shrink and generate more oxygen-containing groups.
The aging process involves a self-amplifying loop: (1) BDOM breaks down under light,generating harmful singlet oxygen (¹O₂). (2) ¹O₂ attacks the MPs, causing further breakdown and releasing more DOM, including MP-derived DOM. (3) This released DOM fuels further ¹O₂ production, accelerating the aging cycle.

Why it Matters

Understanding how BDOM interacts with MPs can help predict their environmental fate and potential risks. This knowledge can inform strategies for managing biochar use and microplastic pollution in water systems.

Looking Forward

Future research could investigate the impact of BDOM on other types of MPs and environmental factors. Developing methods to mitigate BDOM’s negative effects on MP aging could be crucial for protecting aquatic ecosystems.