Hysteretic Behavior of Imidacloprid Sorption-Desorption in Soils of Croatian Coastal Regions
Hysteretic Behavior of Imidacloprid Sorption-Desorption in Soils of Croatian Coastal Regions
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DOI：
10.1080/15320383.2012.697934
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发表时间：
2012-01-01
影响因子：
2
通讯作者：
Milin, Cedomila
中科院分区：
文献类型：
--
作者：
Broznic, Dalibor;Marinic, Jelena;Milin, Cedomila
吸附和解吸是影响吡虫啉在土壤中迁移转化和生物有效性的重要过程。平衡批实验进行了六个沿海克罗地亚土壤。吸附和解吸的平衡实验数据表明，Freundlich方程的拟合效果最好。用Freundlich模型预测的吸附参数K-F（sor）和1/n分别为2.92 ~ 5.74（mg/kg）/（mg/L）（1/n）和0.888 ~ 0.919。结果表明，土壤对吡虫啉的吸附对有机碳含量敏感。Krk土壤中有机碳吸附量最高（4.74%），Zadar土壤中最低（1.06%）。拟合解吸参数值，K-F（DES），始终高于与吸附。对于指数参数1/n，观察到相反的趋势。结果还表明，土壤对吡虫啉的吸附-解吸是浓度依赖性的，即在较低的浓度下，发生较大的吸附百分比和较低的解吸百分比。解吸研究表明，有一个滞后效应，在所有测试的土壤。滞后系数值（H）在0.656至0.859之间变化。研究结果强调，有控制地施用吡虫啉是必须的，特别是在有机碳含量低的土壤中，以尽量减少环境和地下水污染的风险。
Sorption and desorption are important processes that influence the transport, transformation, and bioavailability of imidacloprid in the soils. Equilibrium batch experiments were carried out using six coastal Croatian soils. The equilibrium sorption and desorption experimental data showed the best fit to the Freundlich equation. Sorption parameters predicted with the Freundlich model, K-F(sor) and 1/n ranged from 2.92 to 5.74 (mg/kg)/(mg/L)(1/n), and 0.888 to 0.919, respectively. The sorption of imidacloprid was found to be sensitive to organic carbon (OC) content. The highest sorption was observed in Krk soil (OC 4.74%) and the lowest in Zadar soil (OC 1.06%). Fitted desorption parameter values, K-F(des), were consistently higher than those associated with sorption. The opposite trend was observed for the exponential parameter 1/n. Results also suggested that imidacloprid sorption-desorption by soil is concentration-dependent, i.e. at lower imidacloprid concentrations a greater sorption percentage and lower desorption percentage occurred. Desorption studies revealed that there was a hysteresis effect in all the tested soils. Hysteresis coefficient values (H) varied from 0.656 to 0.859. The study results emphasize that the controlled application of imidacloprid is obligatory, especially in soils with a low organic carbon content, in order to minimize a risk of environmental and groundwater pollution.