中国农业科学 ›› 2007, Vol. 40 ›› Issue (8): 1730-1737 .

• 土壤肥料·节水灌溉 • 上一篇    下一篇

氯嘧磺隆在土壤中的吸附-解吸特性研究

张 伟,王进军,张忠明,秦 蓁   

  1. 西南大学植物保护学院
  • 收稿日期:2006-11-06 修回日期:1900-01-01 出版日期:2007-08-10 发布日期:2007-08-10
  • 通讯作者: 王进军

Adsorption-desorption Behavior and Mechanism of Chlorimuron-ethyl in Soils

  

  1. 西南大学植物保护学院
  • Received:2006-11-06 Revised:1900-01-01 Online:2007-08-10 Published:2007-08-10

摘要: 【目的】对氯嘧磺隆在土壤中的等温吸附-解吸特性进行研究,为其安全使用及对水资源的风险性评价提供理论依据。【方法】采用平衡振荡法和液相色谱法测定氯嘧磺隆在土壤中的吸附-解吸行为,并运用5种数学模型对其在土壤中的吸附-解吸特性及迁移性能进行分析。【结果】氯嘧磺隆等温吸附-解吸曲线符合Freundlich模型,其吸附以物理作用为主,吸附常数(Kads-f)在0.740~9.703之间,其中在2#(江西黏壤土)和3#(江西砂壤土)土壤中的等温吸附线属S型等温吸附线,而在其他土壤中属L型等温吸附线;其解吸存在滞后现象,滞后系数(H)在0.259~0.980之间。此外,Kads-f和解析常数(Kf-des)与土壤有机质含量和黏土含量呈正相关,而与土壤pH值呈负相关,H与有机质含量和黏土含量呈负相关。【结论】氯嘧磺隆在土壤中具有较低的吸附值,在土壤中具有一定的迁移能力,对水体存在风险。土壤有机质含量、黏土含量和pH在吸附-解吸过程中均属支配因素。

关键词: 氯嘧磺隆, 吸附-解吸, Freundlich模型, 滞后现象, 土壤理化性质

Abstract: 【OBJECTIVE】The adsorption-desorption behavior and mechanism of chlorimuron-ethyl in soils were investigated to provide the basic data on evaluating the safety in field and the risk to water resource. 【METHOD】The adsorption-desorption experiment was conducted by the batch equilibration and HPLC techniques, furthermore, data were analyzed with 5 mathematic models to describe the characteristics and mechanism of adsorption-desorption and translocation of the herbicide in soils.【RESULTS】The results showed that the adsorption-desorption isotherms of chlorimuron-ethyl fitted for Freundlich model well, and the physical reaction perform main contribution during adsorption-desorption process. The adsorption values (Kf-ads) of chlorimuron-ethyl in 8 type soils ranged from 0.798 to 6.891. The isotherms of 2# and 3# soils belong to S-type curve, while the isotherms of another 6 type soils belong to L-type isotherm. The results of desorption indicated that the hystersis phenomena appeared during the desorption process, and the hystersis coefficients(H)of the herbicides in 8 soils varied from 0.259~0.980. Furthermore, Kf-ads and desorption values (Kf-des ) increased with OM% and clay content increasing, while decreased with soils pH increasing. H values decreased with OM% and clay content increasing and increased with soils pH increasing.【CONCLUSION】It could be concluded that the low adsorption abilities of chlorimuron-ethyl in test soils and un-reversible adsorption existed in the process, which would induce the great translocation of the herbicide after applied in field. It could be transported to ground or ground water taking risk to environments. Physical and chemical properties of soils, including OM%, clay content and pH of soil, performed the dominating factors during the adsorption-desorption.

Key words: chlorimuron-ethyl, adsorption-desorption, Freundlich model, Hystersis, Physical and chemical properties of soils