NKA大孔吸附树脂对甘草酸三铵盐吸附的动力学和热力学研究

Kinetics and Thermodynamics of Adsorption Glycyrrhizic Acid Triammonium Salt on NKA Macroporous Resin

本文通过静态吸附实验,研究了NKA大孔吸附树脂吸附甘草酸三铵盐过程的吸附动力学和吸附热力学特征,以期为甘草酸大孔吸附树脂分离提纯提供理论支持。实验采用紫外可见分光光度法测定了吸附动力学曲线和不同温度时的吸附等温线,用拟二级动力学方程很好地描述了吸附动力学过程,使用Langmuir方程较好地拟合了等温吸附热力学过程。实验结果显示:NKA大孔吸附树脂对甘草酸三铵盐吸附焓变ΔH吸附和熵变ΔS吸附为正值,自由能变ΔG为负值,吸附活化能为Ea=36.01kJ/mol;该吸附过程是自发的吸热过程,属于物理吸附范畴。

By static adsorption experiments, this paper studied the kinetics and adsorption thermodynamic characteristics of NKA macroporous resin in the process of adsorbing glycyrrhizic acid triammonium salt（GATS）,and provided theoretical support for GATS macroporous adsorption resin separation and purification. Ultraviolet and visible spectrophotometry was used to detect the adsorptive kinetics curve and the adsorption equilibrium curve at different temperatures. The adsorption kinetics behavior was well described by the pseudo-second-order kinetice equation. The thermodynamics behavior was correlated with Langmuir equation. In GATS adsorption process of NKA macroporous resin, enthalpy change ΔH and entropy change ΔS were positive, free energy change ΔG were negative,and adsorption activation energy was 36.01 kJ/mol when temperatures were in the range of 293～313 K. It is indicated that the adsorption was a spontaneous and endothermic process,the process of adsorption was mainly physical adsorption.