异菌脲在土壤中的降解和移动性研究

为明确异菌脲在土壤中的迁移和归趋特征,采用室内模拟方法研究异菌脲在4种不同类型土壤中的降解和移动性以及不同因素对异菌脲降解的影响。结果表明,异菌脲在不同类型土壤中的降解顺序为东北黑土青海草甸土南京黄棕壤江西红壤,降解半衰期分别为7.2、8.6、12.7和16.9 d,异菌脲在4种土壤中均属于易降解农药。土壤湿度越大,异菌脲降解越快,渍水条件下降解速率加快,说明厌氧微生物对异菌脲降解起重要作用。微生物和有机质对异菌脲在土壤降解过程中有一定的促进作用,在微生物、有机质存在的条件下异菌脲降解速率分别提高1.8倍、3.7倍。薄层层析试验表明,异菌脲在南京黄棕壤、东北黑土、江西红壤和青海草甸土的比移值(R_f)分别为0.19、0.17、0.29和0.17,异菌脲在4种土壤中均属于不易移动,土柱淋溶试验结果表明,异菌脲在4种土壤中均属于难淋溶,不易通过淋溶作用造成地下水污染。

Studies on the Degradation and Mobility of Iprodione in Soil

In order to clarify the iprodione environmental fate in soil, the mobility and degradation of iprodione in four kinds of soil were investigated by indoor simulating test. The results showed that the degradation rates of iprodione in four kinds of soil were as follow: Northeast China black soil > Qinghai meadow soil > Nanjing yellow-brown soil > Jiangxi red soil. The half-life of iprodione were 7.2, 8.6, 12.7 and 16.9 d for the four soils, respectively. Iprodione expressed an easy degradation in the four kinds of soils. The degradation of iprodione was accelerated with the moisture of soil elevating. Iprodione degradation was increased in waterlogging treatments due to the anaerobic microorganism which play an important role. The existence of microbial organisms and organic matter in soil led to accelerating the degradation rates of iprodione up to 1.8 folds by the microorganism and 3.7 folds by the organic matter. The soil thin-layer chromatography (TLC) showed that the retention factor value (R_f) of iprodione were 0.19, 0.17, 0.29, and 0.17 in Nanjing yellow-brown soil, Northeast China black soil, Jiangxi red soil and Qinghai meadow soil, respectively. These results indicated that iprodione was difficult to move in the four kinds of soil. The results of soil column leaching test showed that iprodione has a poor mobility in four kinds of soils, which elucidated that iprodione is not easy to pollute the underground water by leaching.