精异丙甲草胺在土壤中的吸附行为及环境影响因素研究

Studies on the Behavior of Soil Adsorption of S-metolachlor and its Environmental Influencing Factors

采用平衡振荡法研究了精异丙甲草胺在粘壤土、粘土及砂壤土中的吸附和解吸附行为。结果表明,3种土壤的吸附等温线均属L型并符合Freundlich模型,吸附常数(Kf)分别为4.01、6.15及8.62,且Kf和1/n(n为经验常数)的乘积与土壤有机质含量呈正相关性。解吸附实验结果表明,精异丙甲草胺在土壤中的解吸附与吸附并不一致,显示出明显的滞后性。温度及pH值等环境因素对吸附影响的结果显示,随温度升高精异丙甲草胺在土壤中的吸附量有所减少,中性环境下土壤吸附量较低。

The adsorption and desorption behaviors of S-metolachlor in three different soils were investigated using the batch equilibration method. The results showed that the adsorption isotherms （L-type） fitted the Freundlich equation well, and the adsorption constant （Kf） of S-metolachlor were 4.01,6.15 and 8.62. Based on the correlation between Kf（l/n） （n is empirical constant） and organic matter content of soils,it was concluded that organic matter content was a dependent factor in the soil adsorption. S-metolachlor desorption isotherms adsorption isotherms. Furthermore, the adsorption showed hysteresis, which did not coincide with concentration of S-metolachlor in soils was reduced at high temperatures, and the adsorption concentration was relative low at neutral condition.