Fluridone, a widely used herbicide, and its main metabolite, fluridone acid, pose significant environmental risks due to their persistence and adverse effects on non-target plants and aquatic organisms. Addressing this, a recent study published in 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 by Chi Wu, Yuzhu Wang, Jihong Liu Clarke, Hang Su, Liang Wang, Olga A. Glazunova, Konstantin V. Moiseenko, Lan Zhang, Liangang Mao, Lizhen Zhu, and Xingang Liu investigated the potential of rice hull biochar (BCR) as a remediation strategy in soil. The findings demonstrate that biochar significantly enhances the sorption and degradation of both fluridone and fluridone acid, while simultaneously promoting the recovery of beneficial soil microbial communities.

The researchers produced rice hull biochar at varying temperatures, from 300 to 700∘C, observing that increasing 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 temperature notably altered biochar properties. For instance, specific surface area values increased from 38.21 to 126.12 m2g−1. The sorption affinity (Kf​) of BCR for fluridone ranged from 409 to 1352, and for its metabolite, fluridone acid, it ranged from 1301 to 6666. This indicates a strong binding capacity, particularly for fluridone acid, which otherwise persists significantly longer in soil (179-306 days) than fluridone (39-179 days).

The study revealed that amending soil with 2% BCR500 (biochar produced at 500∘C) significantly improved the adsorption of both fluridone and fluridone acid, with Kf​ values increasing by 1.30-3.73 times compared to unamended soil. Crucially, biochar accelerated the degradation of these compounds. The degradation half-life (DT50​) of fluridone in biochar-amended soil decreased by 29% to 45%, and for fluridone acid, it decreased by 21.79% to 46.88%. Experiments under sterilized conditions confirmed that biodegradation was the dominant degradation process, accounting for 61.59%-64.70% in unamended soil and an even higher 67.71%-77.67% in amended soil.

Bioinformatic analysis provided critical insights into the microbial mechanisms at play. Fluridone initially reduced the diversity of the soil microbial community. However, after biochar addition, the abundance of microorganisms with degradation functions increased, becoming dominant species. Specifically, higher numbers of degrading bacteria such as Lysobacter, Pseudonocardia, and Sphingomonas were observed. Co-occurrence analysis further demonstrated that biochar strengthened bacterial connections and alleviated the stress caused by fluridone. These shifts in the microbial community structure suggest that biochar not only mitigates the negative impacts of fluridone on microbial diversity but also enhances its degradation potential.

From an applied perspective, this research highlights biochar’s potential as a sustainable remediation strategy for pesticide-contaminated agricultural soils. Its dual function—adsorbing pesticides and stimulating microbial degradation—offers a promising approach to reduce residual pesticide burdens while maintaining soil health.

Source: Wu, C., Wang, Y., Liu Clarke, J., Su, H., Wang, L., Glazunova, O. A., Moiseenko, K. V., Zhang, L., Mao, L., Zhu, L., & Liu, X. (2025). Biochar enhances the sorption and degradation of fluridone and its main metabolite in soil: insights into biodegradation potential and remediation of microbial communities. Biochar, 7(81).