溴氰菊酯在河流底泥中降解动力学

Degradation Dynamics of Deltamethrin in River Sediment

以南京化学工业园内四柳河沿岸河流底泥为试材,研究了微生物对溴氰菊酯的降解及温度与污染物初始质量浓度对降解速率的影响.结果表明,河流底泥中的微生物有很强的降解溴氰菊酯的能力,尤其是表层河流底泥,微生物降解量与降解率在45d时达到了0.711mg.kg-1、62.26%,其半衰期也最小,为21.66d;溴氰菊酯的降解速度与温度正相关,各层河流底泥中的污染物残留量在(30±1)℃时最少,在(10±1)℃时最多;溴氰菊酯的降解速度与污染物的初始质量浓度负相关,各层河流底泥均在污染物质量分数为0.5mg.kg-1时降解速度快,半衰期时间短.

In order to discuss the microbial degradation of dehamethrin （DM）, the sediment of the fourth Liuhe river in Nanjing chemical industrial park were taken as the experimental material, and the effects of temperature and initial concentration of DM on its degradation rate were also studied. The results showed that the mass concentration removed and the rate degradated of DM by microorganisms was high, especially in river sediment of the surface layer, which could reach 0. 711 mg. kg^-1, 62. 260%, and the biodegradation half-live of the treatment was 21.66 d, and the time was shorter than in river sediment of the middle and bottom layer. It proves that radical reaction played the main role in DM degradation by microorganisms. Biodegradation speed of DM showed positive correlation with temperature and negative correlation with initial concentration in all the treatments, residual DM content in all river sediments was lowest at （30±1） ℃ and the highest at （10±1）℃. The DM biodegradation speed was the fastest and the biodegradation half-lives was the shortest when the concentration of DM was 0. 5 mg. kg^-1.