摘要
采用振荡平衡法、土壤薄层层析法和土柱淋溶法研究了噻虫嗪在砂土、粉砂壤土和砂姜黑土等3种不同理化性质土壤中的吸附和淋溶特性,探讨了农药的吸附与淋溶特性与土壤理化性质的关系以及剂型对农药淋溶特性的影响.结果表明,噻虫嗪在3种土壤中的吸附较好地符合Freundlich方程,Kd值分别为砂土1.25、粉砂壤土2.95、砂姜黑土5.10,其大小顺序与Koc值一致.黏粒含量是影响噻虫嗪在土壤中吸附性的最主要因素,有机质含量为次要因素.土壤薄层层析实验和土柱淋溶实验均表明噻虫嗪在3种土壤中的淋溶速率顺序为砂土>粉砂壤土>砂姜黑土,且油悬浮剂、水悬浮剂淋溶量较高,水分散粒剂次之,颗粒剂最低.噻虫嗪存在对地下水污染的潜在风险,特别是在黏粒和有机质含量低的环境下使用时,其风险应该引起足够的重视.
To study the influence of soil basic physical and chemical properties on the adsorption and leaching behavior of pesticides in soil, the adsorption and leaching of thiamethoxam onto three different soils including Sandy soil, Silt loam soil, Shajiang black soil, were conducted by oscillation equilibrium experiment, soil thin layer chromatography and column leaching. The results showed that the adsorption of thiamethoxam in the soils could be well fitted by the empirical Freundich isotherm. The adsorption constants （ Kd ） were 1. 25, 2. 95 and 5. 10 in Sandy soil, Silt loam soil, Shajiang black soil, respectively. Clay content was the dominant factor affecting the adsorption of terbufos in soils, and the soil organic matter content was the next factor. The leaching of thiamethoxam was in the order of Sandy soil〉Silt loam soil〉Shajiang black soil. Higher amount of oil suspended agent and water suspended agent leached out, followed by water dispersible granule, and the granulehad the lowest amount of leaching. These results demonstrated that thiamethoxam has potential risk of contaminating groundwater. Attention should be paid to its application, particularly in the soil of low clay content and organic matter content.
出处
《环境化学》
CAS
CSCD
北大核心
2015年第4期705-711,共7页
Environmental Chemistry
基金
公益性行业(农业)科研专项(201303027)资助
关键词
噻虫嗪
吸附
淋溶
土壤
剂型
thiamethoxam, adsorption, leaching, soil, formulation.
