甲基叔丁基醚(MTBE)在不同粘性土壤中的吸附特性

Absorption characteristics of methyl tert-butyl ether (MTBE) in different clayey soils

土壤对有机物的吸附是污染土壤及地下水原位修复技术中的重要参数。通过静态间歇吸附实验研究了甲基叔丁基醚(MTBE)在不同粘性土壤中的吸附特性。结果表明,MTBE在粘性土壤中的吸附行为均可用线性方程很好描述,粘粒是土壤对MTBE吸附的主要影响因素,吸附常数与土壤粘粒含量呈y=4.382×10-3x-0.817×10-3直线关系。对不同温度下的吸附数据分析发现,粘性土壤对MTBE的平衡吸附量随温度的升高而降低,由吸附热力学推导可得等量吸附焓变ΔH与平衡吸附量无关,且ΔH<0,表明该吸附为放热过程。

The batch experiment was performed to investigate the adsorption characteristics of methyl tertbutyl ether （MTBE） in different clayey soils. The results indicated that linear equation can well describe the soil adsorption behavior of MTBE, and the adsorption capability increases as the clay content increases. The relation- ship between the adsorption constant and clay content in the test soil is the following ：y =4. 482 × 10^-3-0. 864 × 10^-3. Furthermore,the study on the experimental data showed that temperature has obvious effects on the adsorption amount of MTBE. Under the condition of linear adsorption, the enthalpy of adsorption （△H） obtained from thermodynamic analysis is independent of the adsorption amount, and △H 〈 0 indicates that the adsorption is an exothermic process.