Atrazine (AT), a persistent endocri

Atrazine (AT), a persistent endocrine disruptor, has been reported in numerous studies to be present in deep soil and surface water. In this study, algae residue biomass waste was utilized as a raw material to create a biochar-based photocatalyst (ZARB) through the addition of zinc oxide, aiming to investigate its efficacy in the photocatalytic degradation of the triazine herbicide atrazine in the environment. Material characterization reveals that the loaded ZnO adopts a hexagonal wurtzite crystal form, and the band gap of ZARB is lower than that of pure ZnO, as determined using the Tauc plot method. Additionally, ZARB exhibits enhanced photoresponse capabilities. Under the condition of light source UVA+B3 and AT concentration of 20 mg·L−1, the removal rate of 1.5 g·L−1 dosage was 80.8%. On this basis, the presence of NH4+, Mg2+ and Ca2+ will promote the catalytic degradation of AT, while the presence of K+ will inhibit it, and Na+ has no obvious effect in the system. However, the ratio of soil to water and humic acid will significantly affect the catalytic degradation of AT, and there is no obvious interaction between these factors. In the reaction, the degradation contribution of the active material in descending order is O2·– > h+ > OH·. Following the analysis of the post-reaction filtrate, it was hypothesized that the degradation process involves four pathways, namely olefination, dealkylation, hydrolysis reactions, resulting in the formation of a total of eight intermediate products. Overall, the biochar-based photocatalyst developed in this study demonstrates a consistent and efficient atrazine removal effect in the environment. Furthermore, the material exhibits potential for enhanced response in the visible light range, suggesting future improvements in its photocatalytic performance.