3种拟除虫菊酯类农药在不同土壤中的吸附行为特性分析

Analysis of Adsorption Behavior Characteristics of Three Pyrethroid Pesticides in Different Soils

【目的】明确氯氟氰菊酯、联苯菊酯和高效氯氰菊酯在沙土、壤土和水稻土中的吸附特性。【方法】试验采用振荡平衡法和气相色谱法进行研究。【结果】得到3种农药在不同土壤中的吸附方程，符合Freundlich方程；氯氟氰菊酯、联苯菊酯和高效氯氰菊酯在沙土、壤土和水稻土中的吸附系数分别为71．38、134．63、181．77、78．26、199．34、239．13、57．18、222．53、603．72，吸附特性等级为易吸附或较易吸附，平均吸附自由能绝对值范围为18．19-22．03，属于物理吸附。【结论】3种农药在不同土壤中都具有较强的吸附能力。

[Aims] The aims were to evaluate the adsorption characteristics of cyhalothrin, bifenthrin and beta cypermethrin in sandy soil, loam soil and paddy soil. [Methods] The experiments were conducted by batch equilibrium method and gas chromatography. [Results] The results showed that the adsorption isotherm data of cyhalothrin, bifenthrin and beta cypermethrin in sandy soil, loam soil and paddy soil were all conform to the Freundlich equation, and the adsorption coefficients were 71.38, 134.63, 181.77, 78.26, 199.34, 239.13, 57.18, 222.53 and 603.72, respectively. The adsorption characteristic grade were easy to absorb or easier to absorb. The absolute value of average adsorption free energy ranged from 18.19 to 22.03, which belonging to physical adsorption. [Conclusions] Cyhalothrin, bifenthrin and beta cypermethrin have strong adsorption capacity in the three kinds of soil.