哒螨灵农药在土壤中的降解吸附和移动特性  

Degradation,Adsorption and Migration of Pyridaben in Soils

作　　者：蔡玉琪[1] 石利利[1] 单正军[1] 

机构地区：[1]环境保护部南京环境科学研究所,江苏南京210042

出　　处：《农业环境科学学报》2009年第9期1948-1951,共4页Journal of Agro-Environment Science

基　　金："十五"国家科技攻关项目(2003BA614A-08)

摘　　要：采用室内模拟试验方法,研究了哒螨灵在3种土壤中的降解、吸附和移动特性。结果表明,25℃下,哒螨灵在江西红壤、河南二合土和东北黑土中的降解半衰期分别为41.0、55.9和72.2d,属于易降解农药,其降解速率依次为江西红壤>河南二合土>东北黑土。酸性条件有利于哒螨灵的降解,土壤pH值对哒螨灵降解的影响比土壤有机质含量大。3种土壤对哒螨灵农药的吸附均较好地符合Freundich方程,吸附系数Kd值分别为3.35×103、6.17×103和8.48×103,具有极强的吸附性,且土壤有机质含量越高,对哒螨灵的吸附性越强。土壤对哒螨灵的吸附自由能变化均小于40kJ·mol-1,属于物理吸附。哒螨灵在土壤中不易移动,3种土壤薄层移动试验的Rf值均仅为0.05,正常条件下不会造成对地下水的污染。The degradation, adsorption and leaching behavior of pyridaben in three soils were studied in laboratory. The results showed that the degradation half-lives of pyridaben in Jiangxi red soil, Henan fluvo-aquic soil and Northeast black soil were 41.0,55.9 and 72.2 days, respectively, Suggesting that this chemical was degraded rapidly in three soils, and was most easily degraded in Jiangxi red soil. The degradation of pyridaben would be promoted under acidic condition, and the effect of soil pH value on degradation of pyridaben was stronger than that of the content of soil organic matter. Pyridaben was easy to be absorbed by soil （Kd values ranged from 3.35×10^3 to 8.48×10^3）, and its adsorption could finally be denoted by Freundich isotherm. Adsorption of pyridaben was primarily related to soil organic carbon, and got stronger with soil organic carbon increased. The pyridaben adsorption by soil belonged to physisorption with changes of free energy less than 40 kJ·mol^-1. Since the thin layer migration test Rf value of 3 kinds of soil was only 0.05, pyridaben was not easy to migrate in soil and could not cause the ground water pollution under the normal condition.

关 键 词：哒螨灵 土壤降解 吸附 移动 农药 

分 类 号：X592[环境科学与工程—环境工程]