吐温 80 和β-环糊精对土壤-水中除草剂甲草胺分布的影响。
Effect of Tween80 and beta-cyclodextrin on the distribution of herbicide mefenacet in soil-water system.
机构信息
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, PR China.
出版信息
J Hazard Mater. 2010 May 15;177(1-3):1039-45. doi: 10.1016/j.jhazmat.2010.01.025. Epub 2010 Jan 13.
The effect of two solubilizers, Tween80 and beta-cyclodextrin (BCD) on the distribution of herbicide mefenacet (MF) in soil-water system was investigated. The results indicated that in the absence of Tween80 and BCD, the adsorption of MF on the natural soils fitted well with the Freundlich model and the K(f) values were positively related to organic carbon content in the soils. The K(oc) values were in the ranges of 52.7-606.6 L kg(-1). Desorption of MF from the soils was irreversible and positive hysteresis was observed in all the cases. In addition, it was found that the solubility of MF in aqueous phase could be enhanced greatly in the presence of Tween80 and BCD. The adsorption isotherms of Tween80 were fitted well with the linear Langmuir sorption model, and that of BCD fitted well with linear adsorption model. Moreover, it was also observed that the presence of proper concentration of Tween80 and BCD can enhance the transfer of MF from soil phase to aqueous phase. Although BCD presented more adsorption loss than Tween80, a carbon-normalized model suggested the adsorbed BCD had a weaker affinity for MF than the adsorbed Tween80, and experiment results showed the BCD could be a more effective solvent for desorption of MF compared with Tween80. The present study indicated that Tween80 and BCD had great potential in the area of ex situ enhanced soil remediation especially that based on full dynamic mixed model.
研究了两种增溶剂吐温 80 和β-环糊精（BCD）对除草剂甲草胺（MF）在水土体系中分布的影响。结果表明，在没有吐温 80 和 BCD 的情况下，MF 在天然土壤上的吸附符合 Freundlich 模型，K(f)值与土壤中有机碳含量呈正相关。K(oc)值的范围为 52.7-606.6 L kg(-1)。MF 从土壤中的解吸是不可逆的，所有情况下都观察到正滞后。此外，发现 MF 在水相中的溶解度在存在吐温 80 和 BCD 的情况下可以大大提高。吐温 80 的吸附等温线与线性朗缪尔吸附模型拟合良好，而 BCD 的吸附等温线与线性吸附模型拟合良好。此外，还观察到适当浓度的吐温 80 和 BCD 的存在可以促进 MF 从土壤相转移到水相。尽管 BCD 表现出比吐温 80 更大的吸附损失，但碳归一化模型表明，吸附的 BCD 对 MF 的亲和力比吸附的吐温 80 弱，实验结果表明，与吐温 80 相比，BCD 可以更有效地作为 MF 的解吸溶剂。本研究表明，吐温 80 和 BCD 在异位增强土壤修复领域具有很大的潜力，特别是在基于全动态混合模型的修复中。
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