丁草胺在水体中的光解和稻田中归趋的研究

PHOTOTRANSFORMATION OF BUTACHLOR IN AQUATIC SYSTEM AND ITS FATE IN RICE FIELDS

丁草胺在太阳光下，纯水中稳定，田水中消解较快，在模拟太阳光的紫外光下，水体的ｐＨ值和溶解氧对其光解无影响；丙酮可加速其光解；Ｈ_２Ｏ_２可诱发化学氧化和水解，同时加速光解反应，主要光解产物被分离、鉴定。丁草胺在水中不易挥发，能够被土壤吸附，在田间丁草胺在水中消解较快，半衰期＜１ｄ，８－１６ｄ检不出；在土壤中，半衰期为３．３ｄ，３０ｄ后检不出。

Butachlor was stable in redistilled water and broken down faster in rice field water under sunlight.Under simulated sunlight near-UV light, addition of acetone accelerated phototransformation,while pH and dissolved oxygen of aqueous solution had no effect. Dilute hydrogen peroxide initiated chemical oxidation, hydrolysis and greatly increased photolysis rate. principal photodegradation products were separated and identified. Butachlor was essentially nonvolatile and moderately adsorbed to soil. In the field, butachlor dissipated rapidly from water with half-life <1 d and residues below detectability within 8-16 d, and from soil with half-life 3.3 d and residues below detectability within 30d.