茶梗木质纤维素对儿茶素类吸附动力学研究

Adsorption Kinetics of Catechins onto Tea Stalk Lignocellulose

以茶梗为原料制备木质纤维素,通过静态吸附,研究茶梗木质纤维素在绿茶提取物溶液中对儿茶素类的吸附动力学。结果表明,茶梗木质纤维素对儿茶素类总量的吸附等温线符合Freundlich经验方程,随着温度的升高,茶梗木质素纤维素对儿茶素类的平衡吸附量降低;动力学研究数据用拟一级速率方程和拟二级速率方程模拟,其中拟二级速率方程拟合程度更高,在不同温度下利用拟二级速率方程计算的总儿茶素类饱和吸附量与实测值吻合。随着温度的升高,速率常数k1和k2提高,而总儿茶素类的初始吸附速率降低。

Lignocelluloses prepared from woody tea stalk was used to adsorb tea catechins from green tea extract solution by static adsorption, focusing on the study of adsorption isotherm equation and characteristics of kinetics. The results showed that the Freundlich isotherm equation could be used to describe the adsorption of total catechins, and the adsorption capacities of total catechins decreased with the increase in temperature. The equations of pseudo-first-order model and pseudo-second-order model were used for the simulation of adsorption kinetic study. The kinetic results were more fitted to the pseudo-second-order model than the pseudo-first-order model. The saturated adsorption capacities on catechins calculated by the pseudo-second-order model were close to those of experimental data at different temperatures. With the increase in temperature, the rate constants of k1 and k2 are increased, while the initial adsorption rate of total catechins are decreased.