Abstract:

Seven types of macroporous resin were selected to compare their performances in adsorbing and desorbing bamboo flavonoids. AB-8 macroporous resin showed high selectivity and good desorption property. Static sorption experiments were carried out to study the adsorption equilibrium and kinetics of bamboo flavonoids on AB-8 macroporous resin at different temperatures. The results indicated that Freundlich equation was  the best for the description of the adsorption equilibrium of bamboo flavonoids on AB-8 resin，the negative value of ΔG and the positive value of ?S showed that the adsorption was a spontaneous process of increased entropy，and the increase of temperature would benefit the adsorption process. The adsorption heat ?H was 13.45 kJ/mol within the range of hydrogen bond energy；and the FT-IR spectra of AB-8 resins before and after bamboo flavonoids adsorption further suggested that the adsorption of bamboo flavonoids on AB-8 resin was a type of physical adsorption with hydrogen bond. The kinetics results revealed the adsorption followed a pseudo-second-order reaction，and the adsorption rate was mainly decided by the film diffusion.

摘要：

考察了7种大孔树脂对竹叶总黄酮的吸附及解吸特性，发现AB-8大孔树脂具有较高的吸附选择性和良好的脱附性能，并采用静态吸附实验研究了AB-8大孔树脂对竹叶总黄酮的吸附平衡和动力学特性。结果表明，Freundlich方程可较好地描述竹叶总黄酮在AB-8树脂上的吸附平衡；吸附自由能变?G<0，熵变?S>0，吸附为自发的熵增过程，升高温度有利于吸附分离。焓变?H为13.45 kJ/mol，在氢键键能范围内；吸附竹叶总黄酮前后树脂的红外谱图也表明，AB-8树脂对竹叶总黄酮分子的吸附是以氢键形式发生的物理吸附。动力学研究表明，吸附过程符合二级动力学方程，颗粒外的液膜扩散是决定吸附速率的主要步骤。