除草剂草萘胺在土壤-水环境中的吸附行为及其机理

采用高效液相色谱法(HPLC)测定了土壤、胡敏酸及粘土矿物对除草剂草萘胺的吸附效应,并用FTIR图谱分析对其吸附机理进行了研究.结果表明,草萘胺在5种土壤上的吸附均很好地符合Freundlich方程,吸附常数Kf值在3.98～12.82之间.5种土壤对草萘胺吸附容量大小的次序为:黄泥土＞黑土＞黄棕壤＞红壤＞潮土.将吸附常数Kf与土壤的理化性质进行多元逐步回归分析表明,土壤有机碳含量与草萘胺吸附容量呈线性关系(R2=0.997,p＜0.05 n=5).红外光谱分析结果表明,草萘胺可能通过脂肪族分配及疏水吸附等形式与HA发生了结合.

Behavior and mechanism of napropamide adsorption in soil-water environment

Batch adsorption experiments were conducted to measure the sorption of napropamide on five soils, and adsorption mechanism was also analyzed by FTIR spectra. The results showed that the sorption isotherms of napropamide on five kinds of soils could be described well by Freundlich Equation. The K_f values of Freundlich coefficient ranged from 3.98 L·kg^-1 to 12.82 L·kg^-1. The adsorption capacity of five soils decreased with the following order as Typic Fe-leachi-Stagnic Anthrosols > Molli-Gelic Cambosols > Typic Ferri-Udic Argosols > Plinthic Alliti-Udic Ferrosols > Typic Ochri-Aquic Cambosols. A significantly positive relationship was found between K_f and organic carbon content of soils(R²=0.997,p<0.05,n=5), suggesting that organic matter content of soils was the key factor in influencing adsorption. The FTIR spectra showed that aliphatics and hydrophobic- binding were the common mechanism for the complexation of napropamide with HA.