3种三唑类杀菌剂的环境降解特性

摘要

The knowledge of behaviors and fates of 1,2,4⁃triazole⁃typed fungicides in the environment is critical to assess⁃ing their environmental risks. An in⁃laboratory experiment was performed to examine influences of temperature, pH and light on degradation of three kinds of 1,2,4⁃triazole fungicides( epoxiconazole, tebuconazole, and flutriafol) in water and soil. Results show that the photolysis half⁃life of epoxiconazole, tebuconazole, and flutriafol was 0�68, 2�35 and 9�30 h, respectively. Epoxiconazole and tebuconazole were readily photolyzed pesticides, while flutriafol was medium in readiness. In water with pH being 4�0, 7�0 and 9�0 under 25℃,the hydrolysis half⁃life was 120, 131 and 151 d, respectively, for epoxiconazole,and 257, 198 and 187 d for tebuconazole and 204, 182 and 182 d for flutriafol. Hydrolysis of the three types of fungicides was closely related to water pH and their chemical structure. The half⁃lives of epoxiconazole, tebucon⁃azole, and flutriafol were 58�2 to 72�9 days in the red soil of Jiangxi, 182 to 365 days in the paddy soil of Taihu Region and 102 to 161 days in the black soil of Northeast China. The findings of the experiment indicate that epoxiconazole, tebu⁃conazole, and flutriafol all have a long residual period in water and soil, which calls for more attention to their pollution of the environment and monitoring of their application and residues in the environment.%为了掌握三唑类杀菌剂在环境中的行为归趋，评价其在环境中的风险，采用室内模拟试验，对氟环唑、戊唑醇和粉唑醇3种三唑类杀菌剂在不同温度和pH值水体、不同类型土壤以及氙灯光照条件下的降解特性展开研究。结果表明：在4000 lx、紫外强度25μW·cm－2的人工光源氙灯条件下，氟环唑、戊唑醇和粉唑醇的光解半衰期分别为0�68、2�35和9�30 h，氟环唑和戊唑醇属于易光解农药，粉唑醇为中等光解农药；在25℃，pH值为4�0、7�0和9�0条件下，氟环唑的水解半衰期分别为120、131和151 d，戊唑醇的水解半衰期分别为257、198和187 d，粉唑醇的水解半衰期分别为204、182和182 d，3种杀菌剂水解特性差异与水体pH值和农药本身结构相关；氟环唑、戊唑醇和粉唑醇在江西红壤、太湖水稻土和东北黑土中的降解半衰期分别为58�2～72�9、182～365和102～161 d，3种土壤中降解速率从大到小依次为东北黑土、太湖水稻土和江西红壤。3种农药在水体和土壤中的滞留期较长，建议关注其在环境中的污染影响，对其使用和残留状况进行跟踪监测。