Remediation of atrazine in environment by persulfate activation via N/B co-doped Si-rich biochar: Performance, mechanisms, degradation pathways and phytotoxicity

Biochar activated with peroxydisulfate (PDS) has been widely applied in the removal of recalcitrant organic pollutants in the environment, but its wide application is limited by expensive and complex preparation process. In this study, a nitrogen and boron-doped silicon-rich biochar (NBC) was prepared by one-pot synthesis using fungus chaff of Auricularia auricula, diatomite, urea and boric acid as raw materials. The results showed that the specific surface area of NBC was 9 times that of the original, the adsorption capacity of ATZ was increased by 8 times, PDS could be effectively activated, and the removal efficiency of ATZ was as high as 98%. Density functional theory analysis proved that NBC had a lower energy barrier and a higher probability of activating PDS, thereby degrading ATZ through a non-radical pathway dominated by electron transfer. Hydroponic and pot experiments showed that NBC/PDS system effectively restored the growth status, leaf and root morphology, and chlorophyll content of plants, demonstrating the ability to efficiently remediate the toxicity of ATZ on soybean seedlings. This study not only proposed a novel biochar material as an efficient PDS activator but also provided new insights into the practical application of heteroatom-doped carbon catalysts for activating advanced oxidation processes in pollutant degradation.