硝磺草酮在辽宁地区土壤中的吸附、淋溶及降解影响因子

Ads orption,Le aching and Degradation of Mes otrione in Soil of Liaoning

【目的】研究硝磺草酮在辽宁地区4种土壤中的吸附、淋溶及降解影响因子，进而对硝磺草酮在田间安全使用及评价其对地下水源污染风险提供一定的理论依据。【方法】采用振荡平衡法、土柱淋溶法、室内温箱模拟法，分别研究硝磺草酮在辽宁地区4种土壤中的吸附、淋溶及降解影响因子。【结果】硝磺草酮在4种土壤中的吸附符合Freundlich方程，吸附常数介于0．67～5．94之间；在pH值较高的土壤中淋溶较强；在土壤中的降解符合一级反应动力学方程，降解速率分别随土壤PH值升高、土壤含水量的升高加快。【结论】pH值为影响吸附及淋溶的主要因素；降解的主导因素是微生物作用，受光照或温度的影响较小。

[Aims] The aims were to investigate the adsorption, leaching characters and the relation between the degradation of mesotrione and the environmental conditions of soil, which provided theoretical basis for field application and evaluation of groundwater pollution. [Methods] The adsorption of mesotrione in soil of Liaoning was investigated by using the batch equilibration, soil column leaching and indoor incubator. The leaching characters of mesotrione in soil were examined by column leaching method. The relation between the degradation of mesotrione and the environmental conditions of soil was studied. [Results] The adsorption of mesotrione in 4 kinds of soil fitted the Frenndlich equation well and the adsorption constant values of mesotrione were ranged from 0.67 to 5.94. As the pH of soil was higher, the leaching of mesotrione became more easily. The degradation of mesotfione in soil fitted the first-order kinetic equation well and the degradation rate was accelerated by increasing pH value or water content of soil. [Conclusions] The pH value of soil was the main factor affecting the adsorption and leaching. The microbial activity was the dominant factor affecting the degradation of mesotrione in soil, in contrast, light and temperature have little effect on the degradation ofmesotrione.