2,4-D在厌氧条件下土壤中的降解

Degradation of the Herbicide 2,4-D in Anaerobic Soil Conditions

2,4-二氯苯氧酸(2,4-D)是一种世界上广泛应用的除草剂,能够存在于多种土壤环境中,但在某些厌氧条件下会被降解转化。本实验研究了2,4-D在棕壤和黑钙土两种不同土壤中的降解速率及CO2的释放。在两种土壤中分别加入质量为1 mg/kg的2,4-D,培养55 d后,对2,4-D的降解率进行了测定。结果表明,两种土壤的矿化程度没有明显不同,2,4-D的矿化程度均达到70%～80%,而在有氧与厌氧两种不同条件下,土壤中2,4-D的降解存在区别,有氧条件下2,4-D在棕壤和黑钙土中完全降解分别需要约50 d和45 d,而厌氧条件下,在两种土壤中完全降解均需要50～60 d。

2,4-dichlorophenoxyacetic acid（2,4-D） is a herbicide widely used in the world.The compound persists under most environmental conditions,yet it is rapidly transformed under certain anaerobic conditions.A experiment was conducted to determine the degradation of 2,4-D and CO2 evolution in brown earth and chernozems.2,4-D was added to each soil at rates of 1mg/kg of soil.After 55 days of incubation,degradation of the 2,4-D was measured.The results showed that extent of mineralization was about 70-80%,with no significant differences between the two soils.Degradation of 2,4-D was difference under aerobic condition as compared to anaerobic conditions for two soils.Under aerobic conditions,all of 2,4-D was degraded in brown earth and chernozem in approximately 45d and 50d respectively.While under anaerobic conditions,the degradation needed 50-60d.