Francisco Jeane G, Mendes Kassio F, Pimpinato Rodrigo F, Tornisielo Valdemar L, Guimarães Ana C D
a Center of Nuclear Energy in Agriculture , University of São Paulo , Piracicaba , SP , Brazil.
b Department of Agronomy , University of Mato Grosso State , Alta Floresta , MT , Brazil.
J Environ Sci Health B. 2017 Jul 3;52(7):470-475. doi: 10.1080/03601234.2017.1301758. Epub 2017 Mar 29.
This study aimed to evaluate the sorption-desorption and leaching of aminocyclopyrachlor from three Brazilian soils. The sorption-desorption of C-aminocyclopyrachlor was evaluated using the batch method and leaching was assessed in glass columns. The Freundlich model showed an adequate fit for the sorption-desorption of aminocyclopyrachlor. The Freundlich sorption coefficient [K] ranged from 0.37 to 1.34 µmol L kg and showed a significant positive correlation with the clay content of the soil, while the K ranged from 3.62 to 5.36 µmol L kg. The K values were higher than their respective K, indicating that aminocyclopyrachlor sorption is reversible, and the fate of this herbicide in the environment can be affected by leaching. Aminocyclopyrachlor was detected at all depths (0-30 cm) in all the studied soils, where leaching was influenced by soil texture. The total herbicide leaching from the sandy clay and clay soils was <0.06%, whereas, ∼3% leached from the loamy sand soil. The results suggest that aminocyclopyrachlor has a high potential of leaching, based on its low sorption and high desorption capacities. Therefore, this herbicide can easily contaminate underground water resources.
本研究旨在评估三种巴西土壤中氨氯吡啶酸的吸附-解吸及淋溶情况。采用批量法评估了¹⁴C-氨氯吡啶酸的吸附-解吸，并在玻璃柱中评估了淋溶情况。弗伦德利希模型显示对氨氯吡啶酸的吸附-解吸拟合良好。弗伦德利希吸附系数[Kf]范围为0.37至1.34 μmol L⁻¹ kg⁻¹，与土壤黏土含量呈显著正相关，而Kd范围为3.62至5.36 μmol L⁻¹ kg⁻¹。Kd值高于其各自的Kf值，表明氨氯吡啶酸的吸附是可逆的，且这种除草剂在环境中的归宿可能受淋溶影响。在所有研究土壤的所有深度（0 - 30厘米）均检测到氨氯吡啶酸，其淋溶受土壤质地影响。砂质黏土和黏土中除草剂的总淋溶量<0.06%，而壤质砂土中的淋溶量约为3%。结果表明，基于其低吸附和高解吸能力，氨氯吡啶酸具有较高的淋溶潜力。因此，这种除草剂可能轻易污染地下水资源。
