Research Group of Analytical Chemistry and Life Sciences, University of Granada, Granada, Spain.
J Environ Sci Health B. 2009 Nov;44(8):764-71. doi: 10.1080/03601230903238301.
The objective of this work is to gain a better understanding of the fate of carbetamide, as a representative herbicide, after its soil application. To reach this goal, batch and column laboratory experiments were performed and a transport model was proposed consistent with these results. Then field-scale experiments were carried out for two years and the results compared with those that would be obtained from the transport model, once the degradation terms were introduced. All this is done for four different scenarios: first, considering that the soil is under its natural condition; second, the soil is amended with organic carbon by the addition of stabilized sewage sludge; third, considering that the percolating aqueous phase contains a significant quantity of surfactant [Linear Alkyl Benzene Sulfonate, (LAS)]; and fourth, the scenario in which the sewage sludge and the surfactant are present simultaneously. The Freundlich model yields a good fit to the data of the sorption isotherms obtained from batch equilibrium experiments, but the isotherms are close to linear. The batch sorption/desorption kinetic data together with the column and field results indicate that the retention kinetics are quite fast and local equilibrium can be assumed for the description of the sorption phenomenon. Results also prove that carbetamide is moderately retained in the original soil with a mean value of the partition coefficient of carbetamide about 0.46 (L kg(-1)). When the soil is amended with sewage sludge, this coefficient is somewhat lower, about 0.40 (L kg(-1)). A further decrease is observed 0.32 L kg(-1)) when the surfactant (LAS) at critical micelle concentration (CMC) is used. The two-region model yields a good reproduction of the results of carbetamide mobility in the soil, both at the laboratory scale and at the field scale.
本工作的目的是更好地了解carbendazim（一种典型除草剂）在土壤施用后的命运。为此，进行了批量和柱实验室实验，并提出了与这些结果一致的迁移模型。然后进行了为期两年的田间实验，并将结果与引入降解项后从迁移模型中获得的结果进行了比较。这一切都是针对四种不同情况进行的：首先，假设土壤处于自然状态；其次，通过添加稳定的污水污泥来增加土壤中的有机碳；第三，考虑到渗滤水相含有大量表面活性剂[直链烷基苯磺酸盐（LAS）]；第四，同时存在污水污泥和表面活性剂的情况。Freundlich 模型很好地拟合了批量平衡实验得到的吸附等温线数据，但等温线接近线性。批量吸附/解吸动力学数据以及柱和田间结果表明，保留动力学非常快，可以假设局部平衡来描述吸附现象。结果还证明了 carbendazim 在原始土壤中被适度保留，carbendazim 的分配系数平均值约为 0.46（L kg(-1)）。当土壤中添加污水污泥时，该系数略低，约为 0.40（L kg(-1)）。当使用临界胶束浓度（CMC）的表面活性剂（LAS）时，观察到进一步的降低，约为 0.32 L kg(-1)）。两区域模型很好地再现了 carbendazim 在土壤中的迁移性的实验室和田间尺度的结果。
