The adsorption mechanism of tembotrione on modified biochar and its impact on soil microbial communities

Tembotrione, a triketone herbicide with high mobility and persistence, poses significant environmental risks by disrupting soil microbial ecology and threatening crop rotation systems. This study investigates the adsorption mechanism and ecological benefits of hydrogen peroxide-modified biochar (HPBC-700) for mitigating tembotrione contamination in soil environments.

The oxidative modification introduces abundant oxygen-containing functional groups, including hydroxyl, carboxyl, and carbonyl, which substantially enhance the biochar's adsorption capacity and surface reactivity. Density Functional Theory (DFT) calculations and non-covalent interaction analyses reveal that hydrogen bonding and π-π stacking are the dominant adsorption mechanisms. Among the functional groups, carboxyl contributes the strongest binding due to its ability to form dual hydrogen-bond interactions. In addition to physically immobilizing the herbicide, HPBC-700 improves soil microbial diversity and enriches degradation-related functional taxa, particularly Proteobacteria and Acinetobacter, thereby alleviating pesticide-induced ecological stress.

These findings highlight the dual function of HPBC-700 as both an efficient adsorbent and a regulator of soil microbiomes, providing a sustainable strategy for pesticide remediation and agroecosystem restoration. This work advances the understanding of biochar-pesticide interactions and offers new insights into integrating chemical immobilization with ecological recovery for effective soil pollution control. © 2025 Society of Chemical Industry.