三种拟除虫菊酯类农药在砂土和壤土中的淋溶行为

采用土柱淋溶法和气相色谱法研究了3种拟除虫菊酯类农药三氟氯氰菊酯、联苯菊酯和高效氯氰菊酯在热带地区主要土壤类型砂土和壤土中的淋溶特性。结果表明:3种拟除虫菊酯类农药在砂土和壤土中主要残留于第1段土壤 (0～5 cm) 中，且驻留量随土壤深度增大而减少。三氟氯氰菊酯、高效氯氰菊酯和联苯菊酯在砂土中的R_i值分别为52.86%、94.73%和83.19%，在壤土中的R_i值分别为54.70%、77.28%和55.33%，均大于50%。根据农药在土壤中的淋溶性等级划分标准，3种药剂均属于难淋溶农药，不易对地下水造成污染。本研究结果可为热带地区土壤和地下水中农药污染修复提供参考。

Leaching behavior of three pyrethroid pesticides in sandy soil and loam

The leaching characteristics of three pyrethroid pesticides, cyfluthrin, bifenthrin and beta-cypermethrin in the main soil types (sandy soil and loam) in tropical areas were studied by using the soil column leaching experiment and gas chromatography. The results showed that the majority of residues of three pyrethroid pesticides were discovered in the first paragraph (0-5 cm) and the amount of residues decreased with the increase of depth. The R_i values of cyfluthrin, bifenthrin and beta-cypermethrin were 52.86%, 94.73% and 83.19% respectively in sandy soils, and 54.7%, 77.28% and 55.33% respectively in loam, which were all higher than 50%. According to the leaching grade of pesticides in the soil, three pyrethroid pesticides belong to refractory leaching pesticide, which are not easy to cause pollution to groundwater. This study can provide reference for the remediation of pesticide pollution in soils and groundwater in tropical areas.