大孔树脂吸附知母总皂苷热力学研究

Study on Thermodymamics of Adsorbing Timosaponin by Resin

目的:考察SP825、XAD-16、LX-18、XDA-5四种大孔吸附树脂在15℃、25℃和35℃吸附知母提取液中总皂苷的热力学现象。方法:在3种不同温度和一定浓度范围内,通过树脂对知母提取液的静态吸附实验,以紫外分光光度法测定皂苷的含量并绘制吸附平衡线。吸附平衡数据用Langmuir方程和Freundich方程进行拟合,得到SP825、XAD-16、LX-18和XDA-5等大孔吸附树脂对知母总皂苷的吸附焓△H、自由能△G、吸附熵△S。结果:Langmuir方程可以描述4种树脂对知母总皂苷的吸附(R2大于0.98),平衡吸附量qm和KL随着温度的升高而减小,吸附吸附焓△H为负值,自由能△G为正值,吸附熵△S为负。结论:4种树脂吸附总皂苷过程为放热过程,低温有利于吸附,吸附为单分子层吸附,范德华力克服放热过程推动吸附主动进行。XDA-5饱和吸附量最大,吸附效果最好。

Objective：To investigate the absorption phenomenon of the four resins： SP825, XAD-16, LX-18, XDA-5 adsorbing Timosaponin solution under 15 ℃ ,25℃ and 35℃ respectively. Methods ： Through the experiment of resin adsorbing the solution in a static state, and the adsorption balanvced data was fitted with Langmuir Equation, under the three different temperature and a certain concentration. Results ： The Adsorption Thermodynamics parameters of SP825, XAD-16, LX-18, XDA-5 Resins acting upon Timosaponin was obtained. Conclusion ： The ressuh indicated that the adsorbing process was a exothermicing process of, and it was benefit for adsorption by lowering the temperature.