三氟吡啶胺在多介质环境中的降解和吸附特性

    Degradation and adsorption characteristics of cyclobutrifluram in multi-media environment

    • 摘要: 为研究新型杀菌剂三氟吡啶胺的降解、吸附和解吸行为,开展了不同类型土壤、不同水体中三氟吡啶胺的降解和吸附试验。结果表明,三氟吡啶胺在4种土壤中的降解遵循一级动力学模型,半衰期为43.6 ~145 d,其中厌氧微生物、有机质及有机碳含量是影响其降解的重要因素;其5 d水解率为3.3%~5.0%,表现出化学稳定性;光降解半衰期介于10.4~16.0 h之间,属于中等光解农药,且光解速率呈现中性 > 碱性 > 酸性;三氟吡啶胺在4种土壤中的吸附动力学符合准一级动力学模型,最大吸附率为25.1%~39.4%,最大解吸率为7.9%~24.3%;等温吸附过程符合Langmuir模型,有机碳吸附常数为444.3~674.7,属于较难被土壤吸附的农药,地下水污染指数为2.9~3.3,有较高的浸出潜力。综上所述,三氟吡啶胺在4种土壤中属于中等到难降解农药,在水中具有化学稳定性,其土壤吸附能力较弱,易浸出,对地下水系统存在潜在污染风险。

       

      Abstract: To investigate the degradation, adsorption, and desorption behaviors of the novel fungicide cyclobutrifluram, degradation and adsorption experiments of cyclobutrifluram were conducted under different soil types and water conditions. The results showed that the degradation of cyclobutrifluram in four types of soils followed the first-order kinetic model, with a half-life ranging from 43.6 d to 145 d. Among the influencing factors, anaerobic microorganisms, organic matter, and organic carbon content were identified as the crucial regulators governing its degradation process. The hydrolysis rate of cyclobutrifluram within 5 days ranged from 3.3% to 5.0%, indicating its favorable chemical stability. The photodegradation half-life of this fungicide varied from 10.4 h to 16.0 h, classifying it as a moderately photodegradable pesticide, and the photodegradation rate exhibited an order of neutral condition > alkaline condition > acidic condition. The adsorption kinetics of cyclobutrifluram in the four tested soils were well fitted to the pseudo-first-order kinetic model, with the maximum adsorption capacity rate ranging from 25.1% to 39.4% and the maximum desorption capacity rate ranging from 7.9% to 24.3%. Furthermore, the isothermal adsorption process conformed to the Langmuir model, and the organic carbon adsorption constant was in the range of 444.3-674.7, suggesting that cyclobutrifluram was a pesticide with relatively weak soil adsorption capacity. The groundwater pollution index of cyclobutrifluram varied from 2.9 to 3.3, implying a high leaching potential. In conclusion, cyclobutrifluram is a pesticide with moderate to difficult degradability in the four tested soils, possessing chemical stability in water. Meanwhile, its weak soil adsorption capacity leads to easy leaching, which poses a potential pollution risk to the groundwater system.

       

    /

    返回文章
    返回