【摘要】 为评价异恶唑草酮的环境安全性,采用室内模拟试验方法,研究了异恶唑草酮在不同环境介质（空气、水和土壤表面）的挥发特性,在不同质地土壤（潮土、水稻土、黑土和红壤土）的吸附特性,和2种水-沉积物系统中的降解特性。结果表明:异恶唑草酮在潮土、水稻土、黑土和红壤土中的吸附均符合弗罗因德利希（Freundlich）方程,吸附常数值分别为0.640 6、1.376 2、0.816 9和1.289 5,在土壤中属于难吸附农药。异恶唑草酮在湖泊（杭州西湖）水-沉积物系统和河流（杭州运河）水-沉积物系统中的好氧降解和厌氧降解均符合一级动力学方程,好氧降解半衰期分别为73.7 h和75.3 h,厌氧降解半衰期分别为42.3 h和43.0 h,在水-沉积物系统中属于易降解农药。在20～25℃、气体流速为500 mL·min^-1的条件下,异恶唑草酮在空气、水和土壤表面的挥发率均小于1%,属于难挥发性农药。试验结果表明,异恶唑草酮在空气、水和土壤表面难挥发,在土壤中难吸附,在水-沉积物系统中降解快,环境风险较小。更多还原

【Abstract】 In order to evaluate the risk of isoxaflutole in the environment, the volatility, absorption and degradation characteristics of isoxaflutol was examined by a laboratory test. The results demonstrated that absorption of isoxaflutole in four soil types（fluvo-aquic soil, paddy soil, black soil and red soil） accorded with Freundlich equation. The calculated adsorption coefficient of isoxaflutole in fluvo-aquic soil, paddy soil, black soil and red soil was 0.640 6, 1.376 2, 0.816 9 and 1.289 5, respectively. The results indicated that isoxaflutole was hardly absorbed in these four soil types. The degradation of isoxaflutole in lake（West Lake） and river（Grand Channel） water-sediment system accorded with first-order kinetic equation. The aerobic degradation half-life period was 73.7 h and 75.3 h, respectively, and the anaerobic degradation half-life period was 42.3 h and 43.0 h, respectively. The results indicated that isoxaflutole was an easily degradable pesticide in water-sediment system.The volatility rate of isoxaflutole in air, water and on soil surface was less than 1% under the conditions of 20-25 ℃ and 500 mL·min^-1 gas flow rate, indicating that isoxaflutole belonged to a difficult volatility pesticide. In general, isoxaflutole possessed the characteristics of difficult volatility, difficult absorption and fast degradation in water-sediment system, and had a relatively low risk to environment.更多还原