Abstract：
Sulfonamide antibiotics and polycyclic aromatic hydrocarbons (PAHs) often coexist in soil, leading to compound pollution through various pathways. This study focuses on sulfamethazine (SMZ) and PAHs (fluoranthene) as the subject for compound pollution research. Using a soil-groundwater simulation system, we investigated the migration characteristics of SMZ under coexistence with fluoranthene (Fla) and observed variations in the abundance of antibiotic resistance genes (ARGs). Through molecular docking simulations and isothermal adsorption experiments, we discovered that Fla bound with SMZ via π-π interactions, resulting in a 20.9% increase in the SMZ soil-water partition coefficient. Under compound conditions, the concentration of SMZ in surface soil could reach 1.4 times that of SMZ added alone, with an 13.4% extension in SMZ half-life. The deceleration of SMZ\'s vertical migration rate placed additional stress on surface soil microbiota, leading to a proliferation of ARGs by 66.3%-125.8%. Moreover, under compound pollution, certain potential hosts like Comamonadaceae and Gemmatimonas exhibited a significant positive correlation with resistance genes such as sul 1 and sul 2. These findings shed light on the impact of PAHs on sulfonamide antibiotic migration and the abundance of ARGs. They also provide theoretical insights for the development of technologies aimed at mitigating compound pollution in soil.
摘要：
磺胺类抗生素和多环芳烃（PAHs）经常共存于土壤中，通过各种途径导致复合污染。本研究的重点是磺胺二甲嘧啶（SMZ）和PAHs（荧蒽）作为复合污染研究的主题。使用土壤-地下水模拟系统，我们研究了SMZ与荧蒽（Fla）共存下的迁移特征，并观察了抗生素抗性基因（ARGs）丰度的变化。通过分子对接模拟和等温吸附实验,我们发现Fla通过π-π相互作用与SMZ结合，导致SMZ土水分配系数增加20.9%。在复合条件下,SMZ在表层土壤中的浓度可以达到单独添加SMZ的1.4倍，SMZ半衰期延长13.4%。SMZ垂直迁移速率的减速对表层土壤微生物群施加了额外的应力，导致ARGs增殖66.3%至125.8%。此外，在复合污染下，某些潜在的寄主，如Comamonadaceae和Gemmatimonas，与sul1和sul2等抗性基因呈显着正相关。这些发现揭示了PAHs对磺胺类抗生素迁移和ARGs丰度的影响。它们还为开发旨在减轻土壤复合污染的技术提供了理论见解。
