土壤性质对1-丁基-3-甲基咪唑类离子液体吸附/脱附行为的影响

研究了2 种咪唑类离子液体（ILs）—氯化1-丁基-3-甲基咪唑（Bmim]Cl]）和1-丁基-3-甲基咪唑双三氟甲磺酰亚胺盐（Bmim]（CF₃SO₂）₂N]）在16种土壤上的吸附/脱附规律，探讨了土壤理化性质对于吸附/脱附行为的影响。研究发现，Bmim]Cl]和Bmim]（CF₃SO₂）₂N]的土壤吸附系数与土壤阳离子交换量（CEC）呈正相关性，相关系数（R²）分别为0.842 9和0.835 3（P<0.05），表明土壤主要通过静电作用来吸附ILs，而与土壤总有机碳含量（TOC%）的R² 值仅分别为0.003 5和0.073 0（P< 0.01），说明ILs 与土壤有机质的疏水结合作用为相对次要。ILs 阴离子基团对吸附行为有一定的影响，但并不明显。ILs 吸附/脱附的迟滞系数（HI）均小于1,可能与（ILs）在土壤粘土/有机质上的不可逆结合有关。其中，CEC 和Bmim]Cl]和Bmim]（CF₃SO₂）₂N]的HI之间存在较大的相关性（R²分别为0.772 9，0.781 5，P<0.01），说明CEC 对迟滞行为有着不可忽视的影响。

Effects of Soil Characteristics on Sorption-Desorption of 1-butyl-3-methyl-imidazolium-based Ionic Liquids

Effects of soil characteristics on sorption-desorption of 1-butyl-3-methyl-imidazolium-based ionic liquids(Bmim]Cl] and Bmim](CF₃SO₂)₂N])by sixteen natural soils were studied. The value of sorption coefficient K_d of Bmim]Cl] and Bmim](CF₃SO₂)₂N] ranged from 2.5 to 15.9 L·kg^-1 and 2.9 to 16.4 L·kg^-1, respectively. The high positive correlation could be observed between the soil CEC and the K_d of Bmim]Cl] and Bmim](CF₃SO₂)₂N](R²=0.842 9 and 0.835 3, P<0.05, respectively). In contrast, TOC exhibited the weak correlations with Kd(R²=0.003 5 and 0.073 0, P<0.01, respectively). It probably indicated that the electrostatic interaction between ILs cation and nega tively charged soil was the dominant sorption mechanism, while the hydrophobic interaction played the secondary role in ILs sorption.Addi tionally, IL anions showed an insignificant impact on the total sorption of ILs. The sorption-desorption hysteresis indexes(HI)of two ionic liquids by soils were less than 1, which was generally attributed to their irreversible binding to soil components such as clay minerals and soil organic matter. The high linear relationships between desorption HI and CEC were observed(R² values for Bmim]Cl] and Bmim](CF₃SO₂)₂N] were 0.772 9 and 0.781 5, P<0.01, respectively), showing CEC had a considerable influence on the sorption-desorption hysteresis of ionic liquids.